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What is PHP Server Side Scripting?
An Introductory Technical White Paper by webpointmorpheus
Introduction
Client Side
Server Side
PHP
Document Links
©2005 - material compiled by Bob Carnaghi, www.webpointmorpheus.com
- Introduction Top of Page
- In the course of web and internet development, one continuously hears many terms which represent concepts that are totally unfamiliar and foreign. While these technical ideas are not the ‘property’ of a privileged few, and remain open concepts for all to understand, they are rarely if ever explained in common, everyday layman’s terms. This paper attempts to explain the concept of ‘server side scripting’ and one of the methods used to accomplish this task, which is the PHP scripting language.
- Server Side vs. Client Side Scripting Top of Page
- In the execution of a request for a web page, there are three main entities involved. In actuality, there are many, but for the simplification of this article, we are only going to consider the basics of what’s needed. The schematic looks like this:
- Step 1: The Client, or computer making the web page request, sends out the request for the domain name. Since computers on the internet love to think in terms of numbers, and we humans prefer names, there must be a translation of the Domain Name by the Domain Name Server. The request goes to the Client’s Domain Name Server, which ‘resolves’ the domain name. The result of the request is returned as an IP address to the Client.
- Step 2: The Client continues the request by forwarding a request for the specified IP address to the World Wide Web. Computers on the Web help find the Web Server where the requested web page(s) reside. The specific page(s) are returned to the Client appropriately.
- CONSIDER THESE DEFINITIONS:
Client Side: anything that happens on the Client computer.
Server Side: anything that happens on the Web Server.
- Client Side Scripting Top of Page
- There are certain computing tasks which are best delegated to
the Client computer. Up to this point, all of the action
on the Client computer has taken place through the Browser,
down through the Protocol Stack (which is beyond the scope
of this article.) The Browser is a software application
specifically complied for web documents and internet type
interaction. It has certain inherent capabilities, some
of which we’ve already seen in the request process
outlined above. But there are other capabilities within
the Browser.
- In the interest of speed, simplicity, and reliability, if a task can be accomplished on the Client computer, it’s best to approach it that way. One of these tasks is data validation, perhaps through an online form. Another is page formatting, which has been put more and more on the browser. There are many others, and as Browsers become more and more sophisticated and reliable, there is no doubt that they will assume more of a role in the process.
- In essence, the concept of Client Side Scripting is encompassed by anything that can best be accomplished by or on the Client Computer.
- Server Side Scripting Top of Page
- Server Side Scripting encompasses the tasks in the web page request/return cycle that happen on the Web Server. There are many of these tasks which are best suited for the Web Server, and among these concerns are security, reliability, centralization, speed, etc. Online databases are maintained on the Web server
- There are many Server Side Scripting languages available. Some of the popular ones are ASP (Active Server Pages, a Microsoft product,) JSP (Java Server Pages,) Cold Fusion (MacroMedia,) and PHP (an Open Source product,) among others. The essence of a Server Side Script is such that the script itself is rarely or never visible on the Client computer, only the effect of the execution of the script are returned to the Client.
- The PHP Scripting Language Top of Page
- The PHP Scripting Language is an Open Source product. What this means is that the source code for the language is openly available to all developers. This makes improvements possible by a wide range of talented individuals. PHP stands for Preprocessed Hyper Text. The language has been in existence for over 10 years, and is currently in stable release 5. The language is used by many highly trafficked and prominent websites, one of which is the National Weather Service – www.noaa.org.
- PHP is a robust language, which means that it supports a wide variety of properties, methods, and interactions. It is capable of supporting many popular databases, is highly secure, has support for SSL, and has many other highly desirable features. It is lightweight and fast, and is easy to learn and use. There is a wide community of developers who support the language. More information about PHP can be obtained at www.zend.com
- Conclusion Top of Page
- The purpose of this article has been to assist in the understanding of Server Side Scripting. Hopefully, the reader will now have a deeper understanding of the definitions of Client Side process as well as Server Side Scripting.
- Additional Top of Page
- The website process, the way the web works, Search Engines, and other web & internet concepts are often very confusing, especially for the non-technical person. webpointmorpheus has assembled several documents hoping to simplify these topics. This series of documents are the result of a consistent set of questions posed by current, past, and potential webpointmorpheus clientele. The documents are listed below, and are available in printable/downloadable .pdf form.
- SOURCES:
Red Hat Linux Administration, Michael Turner & Steve Shah, McGraw Hill/Osborne
PHP and MySQL Web Development, Welling & Thomson, Developer's Library, 2nd Edition
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Technical Documents avaliable from webpointmorpheus: Top of Page-
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