Introduction of PHP

        PHP was created in 1994 by Rasmus Lerdorf to track the visitors to his online résumé; thus, it originally stood for “Personal Home Page. ” As its capabilities grew (and as more people started to use it), it came to stand for “PHP: Hypertext Preprocessor,” which basically means that PHP handles data before it becomes HTML (HyperText Markup Language).

        According to the official PHP Web site, PHP is “a server-side, cross-platform, HTML embedded scripting language. ” This may sound like a mouthful, but it’s fairly straightforward and meaningful when broken down into its parts.

        First, server-side refers to the fact that everything PHP does occurs on the server (as opposed to on the client, which is the Web site viewer’s computer). A server is simply a special computer that houses the pages that you see when you go to a Web address with your browser.

        PHP is cross-platform, meaning that it can be used on machines running almost any operating system--Unix, Windows NT, Macintosh, OS/2, to name the most popular ones. Again, that’s the server’s operating system, not the client’s. Not only that, but unlike with most other programming languages, your work can be switched from one platform to another with very few or no modifications.

        To say that PHP is HTML embedded means you can put it into your HTML code--HTML being the code with which all Web pages are built. Therefore, scripting with PHP can be only slightly more complicated than hand-coding HTML. If you can make a basic HTML Web page, you can make a dynamic one, too.

        Last, PHP is a scripting language, as opposed to a programming language. This means that PHP is designed to do something only after an event occurs; for example, when a user submits a form or goes to a URL. Programming languages such as Java, C, and Perl can write standalone applications, while PHP cannot. The most popular Web scripting language is JavaScript, which commonly handles events that occur within the browser (for example, when a mouse goes over an image), and is not dissimilar to PHP, although JavaScript is a client-side technology. In fact, if you can already work with JavaScript, you won't have a problem mastering PHP.

Why PHP?

        Webmasters learned a long time ago that HTML alone cannot produce enticing and lasting Web sites. That’s why server-side technologies such as CGI scripts have gained widespread popularity. With them, Web page designers can create dynamically generated Web applications. Often database-driven, these advanced sites require less manual work to update and maintain than static HTML pages, and they allow for e-commerce and other advanced transactions. PHP lets you exponentially expand what you can do with the World Wide Web.

        The advantage PHP has over basic HTML is that the latter is limited and one-sided. Visitors to HTML-only sites see simple pages that aren’t customized for them and don’t display any dynamic behavior. With PHP, you can create exciting and original documents based on many factors--the time of day or whether the user is a repeat visitor, for example. PHP can also interact with databases and files, handle email, and do many other things that HTML cannot.

        But the question remains: Why should a Web designer use PHP to make a dynamic Web site instead of CGI (Common Gateway Interface), ASP (Active Server Pages), or JSP (Java Server Pages)?

        First, PHP is both faster to program in and faster to execute than CGI scripts. I won’t get into too much detail, but suffice it to say that compared to full programming languages like Java, C, or Perl, PHP is much easier to learn and use. People--perhaps like you--without any formal programming training can write PHP scripts with ease after reading a book. In comparison, ASP requires an understanding of VBScript, and CGI requires Perl (or C), both of which are more difficult to learn, not to mention presumably more expensive to develop in.

        Second, PHP was written specifically for dynamic Web-page creation, whereas Perl (and VBScript and Java) were not, inferring that, by its very intent, PHP can perform certain tasks faster and easier than its alternatives.

        My final argument for learning PHP is that, once you do, and as its popularity continues to grow (it is already being used on nearly six million Web sites), you will find yourself well ahead of the learning curve on this, the latest “next big thing” in the world of Internet technology.