PHP (first called “Personal Home Page” language, now called “Hypertext Pre-processor” language) is a server-side, cross-platform, HTML embedded scripting language that lets you create “dynamic” web pages. PHP-enabled web pages are treated just like regular HTML pages and you can create and edit them the same way you normally create regular HTML pages.
PHP is extensively used for web scripts and to process data passed via the Common Gateway Interface (CGI) from HTML forms etc. PHP can be written as scripts that reside on the server and may produce HTML output that downloads to the web browser. Alternatively, PHP can be embedded within HTML pages that are then saved with a .php file extension. The PHP sections of the page are then parsed by the PHP engine on the server and the PHP code stripped out before the page is downloaded to the web browser.
Security – PHP script is executed on the web server, so the client browser can not see the code. This helps prevent “email harvesting” and adds an extra level of security to prevent web page “hijacking”.
Browser Compatibility – Because PHP is a “server-side” language, it is Web Browser “independent”. This means that no matter what web browser (Internet Explorer, Netscape, FireFox, Mozilla and etc.) your viewers are using, the PHP code will execute exactly the same way.
Faster – Even when combined with HTML language, your code will run faster because PHP is a “server-side” program. PHP code is executed on the server and doesn’t have to be downloaded to the client computer for access. Web pages written in HTML and Java must be downloaded and are dependent on the client’s computer performance (i.e. amount of available memory, hard drive space, CPU speed, and etc.).
Dynamic Content - Information in web pages which changes automatically, based on database or user information. PHP language allows certain parts of a web page to “dynamically” update. A static web page, like those written only in HTML or JAVA, require the whole page, including graphics, to reload with the updated information.