| Essential Linux Definitions |
| Term |
Definition |
AIX |
an ibm specific version of UNIX |
~metacharacter |
a metacharacter used to represent a user's home directory |
absolute pathname |
the path to a specific directory that begins at the root of the filesystem |
Accelerated Graphics Port (AGP) |
a videocard expansion slot placed on the motherboard of a computer that permits data transfer rates of over 66 MHz |
accepting printer |
a printer that is currently accepting print jobs into the print queue |
active partition |
the partition that is set to be searched for an operating system per entry in the MBR |
ACPI |
Advanced Configuration and Power Interface (ACPI) |
Advanced Power Management (APM) |
a feature of motherboards controlled through BIOS that shuts off peripheral components in order to save power; typically used on laptops |
Advanced Power Management (APM) |
an established standard for power consumption parameters among hardware and peripherals |
Advanced Technology Attachment (ATA) |
see Integrated Device Electronics |
alias command |
command used to create variables or shortcuts to longer command strings |
ANDing |
a process where binary bits are compared for determining similarities and/or differences |
application specific |
software run on a computer that provides a focused functionality |
architecture |
the construction style of a CPU, sometimes called the computer platform |
archive |
a file or device that contains a collection of data or files that is considered as dated or backed up |
arguments |
additional text that appears after a command name and does not start with a '-dash' character, and specifies further information required by the command to give the desired result or output |
Arithmenic Logic Unit (ALU) |
the portion of the CPU that processes all mathematical and logical instructions |
artistic license |
a type of open source agreement that permits sharing of source code but changing the original code only at the discretion of the owner |
asymmetric multiprocessing |
a multi processor system where each processor is given a set of tasks that are independent of the other processors |
at command |
command that submits jobs to be run at a specific time in the future |
at daemon (atd) |
daemon configured with the at command to run jobs as scheduled by that command |
authentication |
the process of verifying one's identity to gain access to a network or system |
authentication |
the process of verifying a user name and password against the system files that store these items (/etc/passwd & /etc/shadow) |
awk command |
command that searches, filters, and displays text |
background (bg) command |
command used to place a foreground job into the background |
background process |
process that runs in a separate child process from the BASH shell that initiated it, returning control of the shell to the user |
bad blocks |
a block that has become unusable |
baseline |
an instantaneous snapshot measurement of normal system activity under specific load and configuration settings |
BASH shell |
the Bourne Again Shell; the default command-line interface used in the Linux operating system |
BBC Linux |
A bootable OS that fits on a business card size CD |
Beowulf clustering |
a popular and widespread method of clustering computers together using Linux so that a single large task can be spread across several computers to increase functionality |
binary data file |
a file that has been compiled into machine language binary form (1s & 0s) and stores information such as graphics, common functions, etc. for use by compiled programs |
BIOS (Basic Input/Output System) ROM |
a computer chip that contains initial instructions used by the system hardware at boot time |
bit |
the smallest unit of information that can be considered by a computer; binary digit |
block |
a unit of structure given to a filesystem which is typically composed of one or more sectors on a disk or storage unit of some type |
block device |
a storage device represented by a block device file that transfers data to and from the system in data bit chunks via caching in RAM |
boot loader |
a small program that resides on a disk that is loaded by BIOS ROM, and either loads or provides a choice to load an operating system |
boot loader |
program used to load the operating system |
boot.ini |
the Windows NTLOADER configuration file |
broadcast |
a type of communication on a TCP/IP network that sends information to all the hosts on the network |
BSD (Berkley Software Distribution) |
a version of UNIX that was given to the University of California at Berkley by the AT&T lab |
uffer overrun |
a memory problem also known as a memory access exception or buffer overflow wherein a specificly allocated section of memory is overtaxed, misused, or altered |
bunzip2 command |
command that unzips archives that were created bythe bzip2 utility |
burning |
the process of writing files or data to a CD or DVD drive |
burning software |
software for writing files to CD or DVD |
bus |
a connecting pathway or slot from one section of the motherboard to another |
bus mastering |
a system configuration regarding peripheral devices where the peripheral devices perform tasks that are normaly performed by the motherboard CPU, often because the peripheral device has it's own processor of some type |
bzcat command |
command that permits viewing of files within a bzip archive in STDIO |
bzip2 command |
command used to compress files with an algorithm based upon the Burrows-Wheeler Block Sorting Huffman Coding standard |
bzless command |
command that permits viewing of files within a bzip archive in STDIO in a page by page fashion |
bzmore command |
command that permits viewing of files within a bzip archive in STDIO in a page by page fashion |
cache |
any temporary store of computer information or data |
cancel command |
command that will delete print jobs from the CUPS print queue |
cat command |
the 'concatenate' command used to display the contents of entire files to the screen |
cd (change directory) command |
command to change directory in a relative or absolute path type manner |
central processing unit (CPU) |
the processor or microprocessor of a computer that excutes the majority of all calculations that is generated by the computer |
chage command |
command that modifies password expiration information from user accounts |
chains |
components of a firewall that apply rules to network traffic |
character devices |
a storage device file represented by a character device file that transfers data to and from the system one data bit at a time |
checksum |
a calculated value that will verify a file's contents and size |
chgrp (change group) command |
command used to change group ownership of a file or directory |
child process |
a process that was initiated by another process |
chipset |
a common set of ic chips typically on a peripheral device |
chmod (change mode) command |
command used to change the mode or permissions of a file or directory |
chown (change owner) command |
command used to change the owner and group of a file or directory |
chsh command |
command that changes a valid shell to an invalid shell |
classless interdomain routing (CIDR) notation |
a type of IP addressing scheme that establishes a subnet mask by crossing the pre-existing definitions of Class A, B, or C addresses |
clock speed |
the speed of a processor of other hardware device - related to an internal timer cycle |
closed source software |
software that keeps the original source code cloaked and hidden from the general public |
cluster |
a grouping of computers that is configured in such a way as to permit them to function as a single computer; see also Beowulf clustering |
clustering |
the act of configuring computers into a cluster |
color depth |
the total set of colors that a computer is capable of rendering; typically measured in terms of bits: 8 bit; 16 bit; 24 bit; 32 bit |
COM Port |
typically a serial port that uses a DB9 connector to connect various computer peripherals (mice, keyboard, serial printer, scanner, etc.) |
command |
a program that resides on the hard drive capable of being executed when entered into the command line of a shell |
command mode |
one of the two fundamental modes of the vi editor - contrast input mode - command mode permits the execution of text altering type input |
Common Unix Printer System (CUPS) |
printing system that is commonly used on unix systems |
compact disk - read only memory (CD-ROM)s |
a thin, round disk that is used to store, read, and write data that is read by a dedicated drive attached to the computer call the CD ROM Drive |
Complex Instruction Set (CISC) |
a type of processor instruction that is capable of complex calculations on each clock cycle |
complimentary metal oxide semiconductor (CMOS) |
a type of computer chip typically used to store BIOS information |
complimentary metal-oxide semiconductor (CMOS) |
a type of computer chip that requires constant low-level power to maintain configuration settings that are used during the computer boot process |
compress command |
command used to compress files with an algorithm based upon the Lempel-Ziv standard |
compression |
the process that condenses files in size to conserve hard disk space |
compression algorithm |
set of rules or a process that compresses files |
compression ratio |
the ratio of a compressed file to it's uncompressed version |
compressor/decompressor (codec) |
a file that contains instructions for compressing and decompressing data - typically used in media (video/audio) files |
concatenation |
joining together of incremental pieces of text into a larger whole for printing to screen or creation of additional files |
Control Unit (CU) |
the area in a computer processor that enables instruction code or commands to be loaded and executed |
copy in/out (cpio) command |
a common backup utility |
cp (copy) command |
command used to create duplicate copies of files or directories. |
cracker |
a person who uses computers and/or computer software for malicious purpose |
cron daemon (crond) |
the Linux process that runs processes on a recurring scheduled basis; configured through the cron tables (crontab) |
cron table |
a file that specifies user and/or system tasks to be run by the cron daemon |
crontab command |
command that permits viewing and editing user cron tables |
cups daemon (cupsd) |
the daemon that runs the CUPS printing system |
cylinder |
a series of concentric tracks on a hard disk that are used for writing data to the disk via magnet heads |
daemon |
a Linux program or process that typically runs in the background waiting to provide a service |
daemon process |
a system process that typically runs in the background and is not associated with a specific terminal |
data blocks |
an allocation unit within a filesystem wherein the data that defines the contents of a file and the filename are stored. |
database |
a program or method of organizing data into a structured fashion |
Database Management System (DBMS) |
software that creates and/or manages databases |
decision construct |
a programming construct that offers branching of scripts or programs based upon certain established criteria |
default gateway |
the router on a network that is established as the single point of transfer of packets that are outbound from the network to remote networks |
desktop environment |
certain software that works with a Window Manager to provide the essential elements of a GUI environment |
Desktop Switching Tool |
A graphical configuration tool that allows Red Hat users to establish the default desktop environment |
developmental kernel |
a Linux kernel that has been written and is currently being tested; has a characteristic odd minor number, and is considered to be unstable |
device driver |
a type of software that is specifically written to permit instructions to be delivered from an OS kernel to a piece of hardware |
device file |
a file used by Linux commands that serves as a representation of a device on the system; these files use major and minor numbers to reference the proper driver and device on the system |
df (disk free space) command |
command that will display the amount of free space on a disk |
direct memory access (DMA) |
the capability of some peripheral device architectures to bypass the processor and enable the device to talk directly to other peripherals thereby speeding up and enhancing their performance |
direct memory access (DMA) |
a dedicated channel that permits hardware devices to access physical system memory directly |
directive |
a specific instruction within a configuration file |
directory |
a special file (also known as a folder) on a filesystem that is used as an organizational unit to order the system into manageable pieces |
disabled printer |
printer that does not forward print jobs from the print queue to the printer |
disk drive |
a device that contains some form of disk or data storage capability |
Disk Druid |
a graphical tool for partitioning or modifying partitions of a hard drive |
disk imaging software |
a software program that is capable of reading an entire drive or hard drive and creating an image 'snapshot' of the drive |
disk morroring |
a RAID (RAID 1) configuration that consists of two identical drives that are written to in tandem to create a data backup |
disk striping |
a RAID (RAID 0) configuration that writes data across separate hard drives to create a data backup |
disk striping with parity |
a RAID (RAID 5) configuration that writes data to separate hard drives to create a data backup that has enhanced fault tolerance |
distribution |
a particular collection of software that includes a kernel and other applications which are considered to be OSS (Open Source Software) and can function as a full operating system. Typically can be downloaded free via the internet. |
DNS cache file |
a file which refers a host to specific top-level DNS servers |
DNS Servers |
servers that serve to connect human-readable names with machine indentification numeric addresses in order to locate a particular machine or service |
document root |
base directory for content files, especially the HTML web server files |
documentation |
system configuration or instructions that are saved in log files, printed, or online manuals that serve to assist understanding of the system and its operations |
Domain Name Space (DNS) |
a hierarchical namespace that identifies computers by name based upon an assigned IP addresse |
Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM) |
a type of SDRAM capable of faster data transfer rates than traditional SDRAM |
du (directory usage) command |
command that will display the amount of directory usage on a disk |
dual boot |
a configuration that permits the existance of two or more |
dual booting |
the process of having available more than one operating system at boot time |
dual inline memory modules |
an enhanced type of connector for memory modules that has connectors on both sides of the memory stick |
dump command |
utility used to create full and incremental backups |
Dynamic Host Configuration Protocol (DHCP) server |
a server that assigns IP addresses to computers on a defined network |
dynamic RAM (DRAM) |
a type of cost-effective memory that is dependent upon being electronically refreshed in order to maintain its information store |
echo command |
command that displays (echoes) output to the terminal screen (possibly based upon escape sequences) |
edquota command |
command to specify user and group quota limits |
egrep command |
an extension of the grep command that uses extended regular expressions to search for patterns of text in files |
electronically erasable programmable read-only memory (EEPROM) |
an enhanced type of ROM that is capable of being electronically reprogrammed in part or in whole |
ELILO |
a bootloader that is compatible with computers that use the Intel Extensible Firmware Interface (EFI) |
Emacs (Editor MACroS) editor |
a text editor that created by Richard Stallman that is often considered more user-friendly than the vi editor |
enabled printer |
printer that is currently accepting print jobs to the queue |
env command |
command that displays exported environment variables (except special variables) that are present in the current shell |
environment files |
files used immediately upon login to execute commands, typically loading variables into memory for later use or reference |
environment variables |
certain variables which constitute the user environment that store information for programs of the system to use |
erasable programmable read-only memory (EPROM) |
a type or "ROM that is capable of being electronically reprogrammed only in whole |
escape sequences |
character sequences (typically preceded by a \) that have special meaning to the echo command |
Ethernet |
a common network access method especially used in Local Area Networks |
executable program |
a file that can be executed to perform a function of some type |
Explicitly Parallel Instruction Set (EPIC) |
a type of RISC architecture that is used to describe the Itanium processor |
export command |
command that will pass variables to subshells |
ext2 |
a non-journaling file system popular in Linux distributions |
ext3 |
a journaling file system popular in Linux systems |
Extended Multiuser Mode |
also known as runlevel 3; this mode provides certain daemons and networking support |
extended partition |
the portion of a hard drive that is capable of further division into additional logical partitions |
facility |
an area of the operating system where information is collected when system events are logged |
fault tolerant |
the state of sustaining a minimum of down time or data loss in the event of failure |
fdisk command |
command that serves to create, delete, and manipulate partitions on a disk |
fgrep command |
an extension of the grep command that does not use regular expressions |
file command |
a linux command that lists the type of a specific file |
file descriptors |
numeric labels that define command input and output |
File Transport Protocol (FTP) |
a common internet file transportation protocol |
filehandles |
connections made by a process or program to files on a filesystem of some sort |
filename |
a human-readable user friendly identifier given to a file |
filename extension |
a series of letter identifiers that follow a dot (.) after a filename which typically follow a standard naming convention to indicate the type of file |
filesystem |
a type of formatting applied to a storage device that permits storage and retrieval of data (fat, fat32, NTFS, ext, ext2, ext3, ReiserFS, etc.) |
filesystem |
an organizational structure that is applied to a physical storage medium which is used to manage the storage and retrieval of data |
filesystem corruption |
errors in a filesystem that cause data integrity errors |
Filesystem Hierarchy Standard (FHS) |
A Linux defined standard that determines where and how certain system files and directories are structured. |
filter command |
command that passes standard output from one command to standard input of another command |
find command |
the command used on the filesystem that will search for files using various criteria |
FireWire (IEEE 1394) |
an increasingly popular type of connection technology originally developed by Apple Computer, Inc. that permits data transfer rates up to 800 MB per second |
First nondestructive Interactive Partition Splitter (FIPS) |
a configuration utility that can reassign or create partition space from existing free space on FAT16 or FAT 32 filesystems without losing the existing data that is stored on the partition |
firstboot wizard |
a configuration wizard that is seen the first time the Linux operating system is run |
flash memory drive |
a storage medium that uses EEPROM chips |
floppy disks |
a removable storage media 3.5" wide used to store small amounts of data |
foreground (fg) command |
command that moves a background process to the foreground |
foreground process |
a process that runs in the current BASH shell and consumes the shell preventing the execution of any other process until its termination |
forking |
the act of creating child BASH processes from a parent BASH process |
formatting |
the process of placing a filesystem on a disk or drive |
forward lookup |
a name resolution within DNS that resolves the domain name to its IP address |
framebuffer |
an image or representation of video hardware that is used by programs such that they do not need to communicate directly with the video hardware |
free command |
command that will display memory and swap stastics |
Free Software Foundation (FSF) |
An organization founded by Richard Stallman that promotes sharing and collaboration among software developers. |
freeware |
software that is distributed free of charge |
frequently asked questions (FAQs) |
an area of a website that is dedicated on posting answers to questions that are commonly asked |
fsck (filesystem check) command |
command used to check, verify, and/or repair the integrity of a filesystem on a disk |
ftp utility |
a program or utility that converts basic ftp commands to user-friendly (typically GUI) interactions |
full backup |
an archive that includes all the files on a system hard disk |
fully qualified domain name (FQDN) |
the name of a server on the internet in its complete form |
fully qualified domain name (FQDN) |
human-friendly names used to identify computers on a network |
fully qualified domain name (FQDN) |
a host name that follows DNS convention |
fuser command |
command used to identify users or processes that are currently using a specific file or directory |
gateway |
a computer designated as the point of contact between networks or portions of networks; also known as the default gateway |
gedit editor |
a text editor for the GNOME desktop |
General Electric Comprehensive Operating System (GECOS) |
WHAT IS GOING ON HERE???
field in the /etc/passwd file that describes the user account |
GNOME Display Manager (gdm) |
A program used by the GNOME system that provides a graphical login screen |
GNU |
GNU's Not UNIX |
GNU C Compiler (gcc) command |
command that creates a binary compilation of source code |
GNU Image Manipulation Program (GIMP) |
an open source graphical image manipulation program based upon the GTK+ toolkit |
GNU Network Object Model Environment (GNOME) |
a leading graphical environment used on the linux operating system |
GNU Object Model Environment (GNOME) |
one of the two major graphical environments in Linux land |
GNU Project |
a free operating system project initially begun by Richard Stallman |
GNU Public License (GPL) |
A software license that ensures access to the source code of a project for other developers to examine, continue development upon, or improve upon |
GNU zip (gzip) command |
command used to compress files with an algorithm based upon the Lempel-Ziv standard |
Grand Unified Bootloader (GRUB) |
one of the two most popular boot loaders used with the Linux operating system |
Grand Unified Bootloader (GRUB) |
one of the most popular Linux boot loaders |
Grand Unified Bootloader (GRUB) |
one of the two major boot loaders used in Linux land |
graphical user interface (GUI) |
the component of an operating system that offers a visual icon/graphic type interface with point/click capability for interaction with the user. Contrast to command line interface (CLI). |
grep (Global Regular Expression Print) command |
program that searches one or more text files for specific strings (or characters) |
grep (Global Regular Expression Print) command |
one of the most useful commands available in Linux that searches files for patterns based upon regular expressions |
group |
an organizational unit that permits creation of a collection of users for determining ownership and permissions for various system resources |
Group Identifier (GID) |
a unique numeric identification field given to each group on the system |
groupadd command |
command that adds a group to the system |
groupdel command |
command that deletes a group from the system |
groupmod command |
command that modifies a group name or GID on the system |
GRUB root partition |
the partition that contains the second stage of the GRUB boot loader and the /boot/grub/grub.conf file |
grub-install command |
command used to install the GRUB boot loader |
grub-md5-crypt command |
command used to create an encrypted password that protects the GRUB bootloader; stored in the /etc/grub/grob.conf file |
GTK+ toolkit |
a developers toolkit based in the C programming language used by the GNOME and GIMP programs |
gunzip command |
command used to decompress files with an algorithm based upon the Lempel-Ziv standard |
hacker |
a person who has as an intent the exploration of knowledge by using/learning/developing computer skills |
hard disk |
the disk or media that is typically nonremovable and consists of several platters that are configured concentrically |
hard disk drive (HDD) |
a device that is used to read and write date to and from a hard disk |
hard disk quotas |
per user limitations on a disk or drive of number of files or disk space permitted |
hard limit |
an imposed limit that cannot be exceeded |
hard link |
a file that is attached or joined to another file on the same filesystem by sharing the same inode |
hardware |
the physically tangible parts and components of a computer |
Hardware Compatiblilty List (HCL) |
a list of hardware components that have been analyzed and/or tested and are considered to be compatible with a certain operating system |
hardware platform |
the categorization of a computer hardware configuration typically based upon processor type and architecture |
hashpling |
the first line in a script that defines the shell to be used to execute the script |
head command |
a Linux command that displays the beginning lines of a file, the default number of lines being 10 |
home directory |
a (typically) reserved directory created per user for storing personal data |
host ID |
the portion of an IP address that identifies a specific computer or other type of defined host |
host name |
the user-friendly name given to a computer on a network, most often the same name as the FQDN |
host name |
a user-friendly name assigned to a specific computer or other type of defined host |
hostname command |
command that shows or facilitates changing the assigned host name of a computer |
hot fix |
the solution to a software bug typically offered by the vendor/distributor |
hot-swappable |
a component that is capable of being inserted and removed into a computer port without powering down the device or the computer |
HOWTO |
a step-by-step guide typically provided to complete a specific task of installation, configuration, upgrading, or repairing computer software or hardware |
HP-UX |
a Hewlett-Packard brand of UNIX |
Hsync (horizontal refresh) |
the rate in Hertz (cycles per second) that a computer monitor is refreshed horizontally |
Hypertext Transfer Protocol (HTTP) |
the most popular internet text and information transfer protocol |
I/O(Input/Output) address |
a small dedicated area of RAM that is reserved per device for communication between the device and the CPU |
ifconfig command |
command used to display and/or modify the TCP/IP configuration settings assigned to a network interface |
incremental backup |
an archive of a filesystem that contains only the files that were modified since the last full backup |
Industry Standard Architecture (ISA) |
an older (becoming obsolete) motherboard peripheral configuration (connection) limited to 8MHz data transfer |
info pages |
a set of pages available to offer assistance with commands and syntax available by typing 'info command' |
init command |
command that 'initializes' the different runlevels of the operating system |
initialize (init) daemon |
the first process run by the Linux kernel; initializes the inherent daemons for the runlevel that is initialized |
initstate |
see 'runlevel' |
inode |
the portion of a file that stores metadate on the attributes, permissions, location, ownership, type, etc. of a file |
inode table |
a collection of all the inodes for all the files and directories of a filesystem |
Input/Output (I/O) Address |
an address in physical memory that is assigned to a hardware device |
Input/Output Statistics (iostat) command |
command that will display block device statistics |
insert mode |
one of the two input modes of the vi editor what allows text to be inserted into the document |
insmod command |
command that inserts a Linux kernel module |
installation log files |
files that are created during OS installation for review and troubleshooting after the installation |
Integrated Drive Electronics (IDE) |
Also known as ATA, a configuration architecture that permits up to four devices to be connected to a motherboard by ribbon cables |
interactive mode |
a system of prompts that safetuards accidental deletion of a file or directory |
International Standards Organization (ISO) images |
single files that contain a full snapshot of information from a drive |
Internet |
the interconnection of various computer networks which include but are not limited to business, education, governement, personal, and private networks to permit communication or sharing of data/resources |
Internet Protocol (IP) address |
a series of numbers that are unique to machine identification on a network or the Internet at large. |
Internet Protocol (IP) Address |
a series of 8 bit numbers that are assigned to a host for identification on a network |
Internet Protocol (IP) Address |
a numeric address that is used to uniquely identify a computer on a given network |
Internet Super Daemon (xinetd) |
the network daemon responsible for initializing and configuring those services on a Linux system |
Interrupt Request (IRQ) |
a unique channel that permits a computer device to communicate with the CPU |
Interrupt Request (IRQ) |
a method of allocating processor time, resources, and priority among hardware and peripheral requests |
Intrusion Detection System (IDS) |
a security feature that is capable of detecting attempts at unauthorized access to the system |
ip command |
command that can be used to manipulate and configure the route table in a Linux system |
IP forwarding |
sending or transferring IP packets to another TCP/IP network, also called Routing |
iptables command |
command used in Red Hat Fedora to configure the firewall |
iterative query |
a DNS name resolution that does not use the top level DNS servers |
jabbering |
process wherein (typically older, legacy, or failing) devices send large amounts of data to the processor |
jobs command |
command that will display the list of processes that are currently running in the background |
journaling |
the quality of a file system that makes it possible to retain crucial data in the event of a system failure |
K Desktop Environment (KDE) |
one of the two main desktop environments used in Linux land; created in 1996 by Matthias Ettrich |
K Window Manager (kwin) |
the Window Manager used by the KDE desktop |
KDE Display Manager (kdm) |
A program used by the KDE system that provides a graphical login screen |
kedit editor |
a text editor for the KDE desktop |
kernel |
the essential core program/software of the operating system to integrate computer hardware with user software. The Linux kernel is the common element that appears in all Linux distributions, user and service software being tailored to the installation. |
kernel parameters |
certain portions of information passed to the kernel to alter it's behavior |
Kickstart Configurator |
the graphical utility used to create a kickstart file |
kickstart file |
a file that is created to automate the Linux installation process |
kill command |
command that will terminate a process |
kill signal |
a specific signal sent to a process by the kill command; note that there are differing levels of kill signals that will affect different processes in different ways |
killall command |
command that kills all instances of a process by command name |
Knoppix Linux |
CD bootable OS for use in emergencies or on a foreign computer |
Kommon Desktop Environment (KDE) |
one of the two most popular desktop environments used in the Linux distributions. |
kudzu program |
program that will detect and install support for new hardware |
large block addressing 32-bit (LBA32) |
the capability of specifying a certain hard drive addressing scheme that enables drives over 2GB. LBA is necessary only if large hard disks are not supported by the system BIOS |
ldconfig command |
command that works to configure shared libraries by updating the /etc/ld.so.conf and /etc/ld.so.cache files |
ldd command |
command that works with shared libraries and their use or connection to specific programs |
less command |
a Linux command that permits viewing a file page-by-page on the computer screen |
Level 1 (L1) cache |
cache memory that is stored in the CPU itself |
Level 2 (L2) cache |
cache memory that is stored in a separate chip, or in the CPU itself; if the L2 cache is integrated into the CPU, a separate L3 cache is utilized |
Level 3 (L3) cache |
additional cache memory that is stored in a chip separate from the CPU on the motherboard |
lilo command |
command that reinstalls the LILO bootloader from configuration information in /etc/lilo.conf file |
Line Printer Daemon (lpd) |
a print system that is used on older Lynux systems |
linked file |
a special file that represents the same data as other files |
Linus Torvalds |
A Finnish graduate student who initially developed and distributed the first Linux kernel, and published it under the GNU Public License. |
Linux |
the operating system kernel developed by Linus Torvalds. This kernel is open source, and is continually improved and revised by members of the open source community. |
Linux Documentation Project (TLDP) |
A large collection of Linux resources, information, and how-to files published, supplied, and maintained by the Linux community. |
Linux Loader (LILO) |
one of the most popular Linux boot loaders |
Linux Loader (LILO) |
one of the two major boot loaders used in Linux land |
Linux User Group (LUG) |
A fellowship of individuals that is bound by a common interest in learning and using the various distributions of Linux and other open source software. |
ll command |
a command alias that is equivalent to 'ls -l' |
ln (link) command |
command that creates symbolic or hard links to files or directories |
local area networks (LAN) |
a type of network where all the hosts are in close physical proximity |
locate command |
command that will locate files from a file database |
locking an account |
the act of temporarily suspending a user account |
log file |
a very useful file that stores data based upon a certain interaction or series of interactions with a system service |
log file |
file that contains system or software information |
logical drive |
smaller divisions of an extended partition on a hard drive |
Logical Unit Number (LUN) |
a unique SCSI identifier that is assigned to devices in a SCSI chain |
logrotate command |
command that rotates log files; see /etc/logrotate.conf for configuration info |
lp command |
command that sends print jobs to the CUPS print queue |
lpadmin command |
command that administrates printers in the CUPS printing system |
lpc command |
command that permits viewing and control of printers in the LPD printing system |
lpq command |
command that permits viewing of print jobs in the print queue of the LPD printing system |
lpr command |
command that creates print jobs in the print queue of the LPD printing system |
lprm command |
command used to remove print jobs from the queue of the LPD printing system |
lpstat command |
command that permits viewing print queue and printer information in the CUPS printing system |
LPT port |
a db-25 type connection to the mainboard that permits connection of peripheral devices, typically a printer; also called a parallel port |
ls command |
a Linux command that lists the contents of a directory and the specific information about those contents |
lsmod command |
command that lists the current modules installed on the Linux kernel |
magnetic tape (mt) command |
command that will control magnetic tape devices |
Mail Delivery Agent (MDA) |
the software that runs on a computer that downloads email from a mail transfer agent (MTA) and makes it available to the mail user agent (MUA) to be read by the end user. |
Mail Transfer Agent (MTA) |
an email server that actually sends, forwards, or transfers email |
Mail User Agent (MUA) |
A program or software that makes email readable by the end user. |
mail utility |
a mail user agent |
mainboard |
a circuit board the permits connection of devices and peripherals via slots or ports and integrates their operation into a functional computer; also known as the motherboard |
major number |
The first number in the sequence of digits which identifies a release of the Linux kernel - denotes a major change or revision. |
major number |
an identification number within a specific scheme that the kernel uses to identify which hardware device driver to call for compatible interaction; the revision number given to the kernel release |
Mandrake |
A major release of Linux distributed in North America by MandrakeSoft. |
manual pages |
a set of local documentation available by typing 'man command' that provides command syntax documentation; the 'man' pages |
Master Boot Record (MBR) |
an area separate from the standard hard disk partitions that stores information about the partitions and boot loaders |
Master Boot Record (MBR) |
a small area located on the first sector of the first hard drive typically defining partitions and boot loaders |
master DNS server |
also called Primary DNS server, the server that contains a read/write copy of the domain names listed for that zone |
maximum resolution |
definition of the best clarity for an image that is displayed on the screen typically stated in |
mcedit (Midnight Commander Editor) |
a terminal text editor considered to be user-friendly because of its support for regular expressions and the computer mouse |
media access method |
a system that defines computer share access to the physical portion of a network |
metacharacters |
key characters or combinations with special meaning to the Linux operating system |
Metacity Window Manager |
the Red Hat Fedora Core 2 default GNOME Window Manager |
mingetty |
program used to display a login prompt for a character-based terminal |
MINIX |
a mini-UNIX operating system that was publically accessible and paved the way for the initial development and release of the Linux kernel. |
minor number |
the number that is the second sequence of digits in the identifying series of numbers of the Linux kernel, which denotes minor modifications. If the number is odd, it denotes a development (unstable) version, if the number is even, it denotes a production (stable) release of the kernel. |
minor number |
an identification number within a specific scheme that the kernel uses to identify which hardware device driver to call for compatible interaction; the revision number given to the kernel release |
mkbootdisk command |
command that will create a Linux boot floppy disk |
mkdir (make directory) command |
command that creates folders or directories |
mkfs (make filesystem) command |
command that formats a disk or creates a file system |
mknod command |
command that re-creates a device file using the provided major & minor number, as well as device type (block or character) |
mode |
the portion of an inode that stores information on access permissions |
modprobe command |
command that will insert a kernel module and all its required modules |
monitoring |
the process that observes and/or records the activity on a system |
more command |
a Linux command that will display a file page-by-page and line-by-line on the computer screen |
motherboard |
see mainboard |
mount command |
command that mounts filesystems to a specific named directory for access |
mount point |
the specific named directory in a filesystem to which something is mounted |
mounting |
the process of associating a device or filesystem to a folder to permit access |
mouseconfig |
command used to configure the mouse for use by X Windows |
multicast |
a type of communication on a TCP/IP network that sends information to a specific group of computers |
multihomed hosts |
computers that have more than one network interface |
Multiple Processor Statistics (mpstat) command |
command that displays statistics for a CPU |
Multiplexed Information and Computing Service (MULTICS) |
An AT&T Bell Lab operating system developed and used in the 1960's. |
multitasking |
a type of operating system that has the capablity to manage multiple tasks simultaneously. |
multiuser |
the quality of an operating system that provides access to more than one user simultaneously |
Multiuser Mode |
also known as runlevel 2; this mode provides most daemons and some networking daemons |
mutt utility |
a common mail user agent on Linux systems |
mv (move) command |
command that will move or rename files and directories |
named pipe file |
a temporary connection that is represented by a file on the system that sends (or pipes) information from one command or process to another |
nedit editor |
a Linux text editor that is graphically enhanced |
netmask |
also called the network mask or subnet mask; a portion of an IP address that is used to distinguish network identity as opposed to individual computer identity |
network |
a system of two or more computers that are joined together in order to exchange information |
Network File System (NFS) |
a distributed filesystem that permits sharing of different file types over a network |
network ID |
the portion of an assigned network address that identifies the specific network to which the host belongs |
network interface card (NIC) |
a hardware device that is capable of connecting the computer to a network or other computers |
newgrp command |
command that will temporarily change the primary group of a user |
newsgroup |
an Internet service that provides focused information about a specific topic. Newsgroups are typically posted to by users who are currently involved in the field of the newsgroup topic, and the service provides the latest information as posted by involved users. |
nice command |
command used to change process priority at initialization of the process |
nice value |
a value assigned to a process that categorizes the process by priority; lower values have a higher priority |
nmap (network mapper) command |
command that uses the nmap utility to scan a computer for open or configured ports |
nohup command |
command that prevents other processes from exiting when the parent process is killed |
NTLOADER |
the typical Windows boot loader; used by Windows NT, 2000, and XP |
ntsysv |
a utility that can be sued to alter the daemons which are initialized in each runlevel |
octet |
the portion of an IP address that represents eight binary bits |
od command |
a Linux command that will display the contents of a file in octal format |
Open Source Software (OSS) |
a system of software that provides the source code of the software freely to anyone who wants to examine, improve, or utilize it. |
operating system (OS) |
a specific software arrangement that provides direct access to computer hardware |
options |
command line parameters that are passed following a '--double dash' to alter the behavior of the command |
other |
a conceptual owner referenced in file and directory permissions that refers to 'everybody' |
overclocking |
the act of configuring a cpu to run at a higher clock speed than that for which it is rated |
owner |
the person or entity that is listed in the permissions for a file or directory typically having capability to change permissions on the file or folder |
package dependencies |
a list of packages that are required for proper installation and operation of a package that is being installed on a system |
package manager |
software that is used to install, query, update, maintain, and/or remove other software from a system. Information about the installed software is typically maintained in a software database for ease of access and current statistics. |
package manager |
a system of management for installation, query, removal, and configuration of packages on a Linux system |
Packet Internet Groper (ping) command |
command used to check connectivity on a TCP/IP network |
packets |
packages or datagrams that contain a body of information which has been broken down into small portions for transmission across the network |
parallel port |
see LPT port |
parent process |
a process that starts or initializes other (child) proceses |
parent process ID (PPID) |
the PID of the process that started the process |
partition |
a section of a hard drive that is clearly physically defined and provides the formatting of a filesystem |
partitions |
a portion of a hard drive created from an extended partition and formatted with a specific file system |
passwd command |
command that will modify a user's password |
patch command |
command that applies an upgrade or update to the Linux kernel |
PATH variable |
a system variable that lists directories to be searched for executable files |
peripheral component |
external components that connect to the motherboard of a computer per connectors, slots, or ports and provide functionality; i.e. keyboard, mouse, video adapter, etc. |
Peripheral Component Interconnect (PCI) |
a DMA capable motherboard connection specification in wide use today that offers data transfer rates up to 33 MHz |
permissions |
a list that identifies who can access files and folders and to what degree of access they are permitted |
Personal Computer Memory Card International Assn. (PCMCIA) |
a motherboard connection specification in wide use especially on laptops that permits expansion and additional functionality |
physical memory |
a storage area for data that is directly wired through circuits and busses to the processor |
pipe |
a sequence of commands that are connected by a pipe (|) character which send the output of one command as input to the next command |
Plug-and-Play (PnP) |
a computer specification that permits devices to be configured automatically upon installation or boot with IRQ, I/O address, and DMA settings |
Plug-and-Play (PnP) |
a system of auto configuration of peripheral devices (IRQ, I/O address, DMA) by the system BIOS |
Pluggable Authentication Modules (PAM) |
component of a Linux system that processes authentication requests by daemons on a Linux system |
polling |
the act of querying devices for status and request information |
port |
a number for a service that is used on a system |
Power On Self Test (POST) |
a low-level set of hardware tests run on a computer when the machine is first initialized |
power-on self test (POST) |
the initial routine run on computer hardware by BIOS when power is turned on to the computer before the operating system loads |
primary DNS server |
see master DNS server |
primary group |
the default group of a user |
primary group |
the group specified for a user in the /etc/passwd file that determines the group owner for all files created on the system by the user |
primary partitions |
any of 4 permissible divisions on a hard drive to which filesystems are applied and data is stored |
print job |
a collection of grouped information sent to a printer for printing to paper or other media |
print job ID |
a unique numeric identification field given to a print job |
print queue |
a directory used by the system as a temporary holding area for submitted print jobs |
Printer Configuration tool |
a graphical configuration tool for configuring system printers |
printing |
the process of sending print jobs from the print queue to the printer |
priority |
a relative importance given to a print job or other process when compared to other jobs or processes |
proactive maintenance |
maintenance that is performed on the system by planning, and is applied before any system failures or problems |
process |
a program that is loaded into memory, or 'software in action', that provides a certain service or performs a specific task |
process |
a program that is currently loaded into memory and running |
process ID (PID) |
a unique numerical identifier assigned to a process when it initializes |
process priority |
a numerical priority number assigned to a process that determines the amount of processor resources that the process is to receive; lower numbers have higher priority |
process state |
the current state of a process as viewed from the processor; typically, running or sleeping |
production kernel |
the Linux operating system kernel that is enumerated by an even minor revision number, and is taken to be of a stable nature |
program |
a set of instructions that interact with computer hardware, most often using human input, to produce a desired outcome from the computer |
program |
a structured set of commands or instructions that are in executable format which will initiate a process and/or execute a task for a specific outcome |
programmable read-only memory (PROM) |
a ROM type chip the permits data to be written only once |
programming language |
a set of rules or the syntax for writing a set of instructions into program code |
protocol |
a set of communication rules used on a network or between hosts |
ps command |
command used to return information about the currently running processes on a system |
PS/2 ports |
a type of computer connection that is typically used for mice and keyboards |
pwconv command |
command that enables use of the /etc/shadow file for creating more secure encrypted password information |
pwd (print working directory) command |
a Linux command that will show the user the absolute path to the current working directory |
pwunconv command |
command that disables use of the /etc/shadow file for creating more secure encrypted password information |
Qt toolkit |
the software toolkit native to the KDE |
queuing |
see spooling |
quota command |
command that will show the disk quotas imposed on a user |
quotaoff command |
command that will remove disk quota |
quotaon command |
command that will enable disk quota |
quotas |
limits of filesystem storage that are imposed upon a user |
Rambus Dynamic Random Access Memory (RDRAM) |
a proprietary type of dynamic ram developed by the Rambus Corporation |
random access memory (RAM) |
a type of memory chip that stores data dependent upon an electrical charge and loses the data when the system loses power |
reactive maintenance |
maintenance that is performed on the system when something has gone wrong, or in a crisis situation |
read command |
command used to read standard input from a user or command into a variable |
read-only memory (ROM) |
a type of memory chip that stores data regardless of electrical power loss |
recursive |
a term referring to a folder (itself) and all its contents, including additional subfolders |
recursive query |
a DNS name resolution that uses the top level DNS server |
Red Hat |
the most popular release of Linux, distributed in North America by Red Hat, Inc. |
Red Hat Package Manager (RPM) |
the most commonly used package manager in Linux land |
redirection |
the process of changing the default or projected locations of standard input, standard output, or standard error |
Reduced Instruction Set Computers (RISC) processors |
relatively fast computers that are less expensive than CISC, and capable of understanding small instruction sets |
Redundant Array of Independent Disks (RAID) |
a configuration standard that combines several disks into one volume to increase available space and improve fault tolerance |
redundant array of inexpensive disks (RAID) |
a type of hard drive configuration that connects the drives in such a way as to provide fault tolerance |
refresh rate |
the rate at which a video monitor display is refreshed; measured in Hz (Hertz - cycles per second) |
regular expressions (regexp) |
a series of special metacharacters used to match patterns of text, typically inside files, used by certain commands or text editors |
REISER |
an ever-more popular journaling filesystem used in Linux |
rejecting printer |
a printer that is currently not accepting jobs into the print queue |
relative pathname |
the path to a specific directory or location in a directory structure based upon a relative starting point, typically from the current working directory |
removable media |
storage media that can be readily removed from a computer |
renice command |
command that will reassign a nice value to a process |
repquota command |
command that will report the quotas for a filesystem |
resolution |
the total number of pixels (divisions) that a computer monitor can be divided into |
restore command |
command used to extract backup files that were created by the dump command |
reverse lookup |
a name resolution within DNS that resolves an IP address to the domain name |
revision number |
the number after the second dot in the version number nomenclature that defines the Linux kernel, and identifies the specific release of the kernel |
rm (remove) command |
command used to remove files and directories |
rmdir (remove directory) command |
command used to remove empty directories |
rmmod command |
command that will remove a kernel module |
rogue process |
a process that has gone hog wild on the system consuming more resources than needed |
root filesystem |
filesystem that contains core essential files of the operating system |
route command |
command for configuring a route table |
route table |
a table of information that lists networks and their connection to network interfaces |
routers |
devices which can transfer data packets between networks |
routing |
the forwarding of packets tospecific hosts in another network |
rpm command |
command native to the RPM utility |
rules |
guidelines within a firewall that match network traffic in order to determine which packets should be forwarded or dropped |
runlevel |
a definition of type or collection of deamons that are initialized at boot by the Linux system |
runlevel command |
command used to display the current or most recent runlevel |
scalability |
the capabliity of computers or software to grow with the least amount of unnecessary overhead or inefficiency |
SCSI |
Small Computer System Interface |
SCSI ID |
a number assigned to SCSI devices in a SCSI chain |
search engine |
an Internet portal that returns a set of resultant web pages or references to a search query |
secondary DNS server |
DNS server that backs up the primary DNS server with a read-only copy of the zone - see also Slave DNS server |
sector |
the smallest unit of division of a hard drive, typically arranged into concentric circles called tracks which are combined into blocks |
Secure Shell (ssh) |
a secure utility capable of encryption for connecting to remote Linux hosts |
sed command |
command (String Editor) that searches, filters, and manipulates text |
serial port |
see COM port |
server |
a computer that is configured to permit other computers to connect to it from across a network. Typically, the server provides key processes, data, security or authentication to/for the network |
server closet |
a secure location where servers are stored |
server services |
services offered by a computer for other machines across a network |
set command |
command used to view the variables in a shell (except the special variables) |
setserial command |
command that configures or sets the parameters of a serial device |
shareware |
programs that are offered at minimal cost to the end user. Typically these programs run for a free trila period, then require payment to continue use. |
shell |
a type of user interface used in Linux for entering commands and interacting with the operating system |
shell scripts |
text files that contain sequences of commands that the shell interprets and executes |
single inline memory modules (SIMM) |
an older (becoming obsolete) type of computer memory socket that permits data transfer on one side of the chip only |
Single User Mode |
also known as runlevel 1; a mode that initializes a single terminal and a limited set of services, typically no networking, and used for troubleshooting or configuring the system |
skeleton directory |
a directory that contains essential user files that are copied to all new users' home directories upon creation; /etc/skel |
slave DNS server |
DNS server that contains a read-only copy of the zone as a backup to the master DNS server |
Small Computer Systems Interface (SCSI) |
a type of computer controllerspecification that permits connections of several devices through the controller to the motherboard - typically SCSH hard drives, tape drives, & CD/DVD drives |
small outline dual inline memory modules (SODIMM) |
a type of DIMM that is smaller in profile typically used in laptops and Macintosh computers |
smbclient utility |
a utility that is capable of connecting Linux and Windows networks |
smbmount command |
command used to mount directories that are on Windows networks to mount points on Linux servers |
smbpasswd command |
command that generates and configures the Samba password for a user |
socket file |
a named pipe that connects processes on two different computers, also capable of being represented by a special file type on a system |
soft limit |
an imposed limit that can be exceeded for short periods of time |
software |
certain programs that provide functionality to a computer user. Anything in the computer that is coded. Contrast hardware, which is a physical object. |
Solaris |
A version of UNIX that was designed by Sun Microsystems from the original AT&T source code. |
sort command |
command that sorts the lines of a file |
source code |
The original code from which software programs are compiled or developed. |
source file/directory |
the portion of a command that refers to the file or directory from which information is referenced |
spanning |
a RAID (RAID 0) specification that allows two or more devices to be represented as a single volume |
special device file |
a special file in the system that is used to represent a hardware device |
spooling |
the process of accepting a print job into the print queue |
stand-alone daemons |
daemons that are capable of configuring themselves when started without assistance from xinetd |
Standard Error (stderr) |
file descriptor that represents any error messages generated by commands |
Standard Input (stdin) |
file descriptor that represents input to a command during execution |
Standard Output (stdout) |
file descriptor that represents output from a command |
static RAM (SRAM) |
a more expensive type of RAM that can tolerate short interruptions to the applied electrical charge without data loss |
strings command |
a Linux command used on binary files to find and display text characters |
su (switch user) command |
command that permits switching the current user account |
subdirectory |
a directory that resides within another directory on a filesystem |
subnet mask |
a series of 4 octets of numbers that determine the host and network identification of a computer or other network connected entity |
subnetting |
the process of dividing a large network into smaller |
