A static web page never changes, unless a person specifically edit the page. A dynamic web page can be different every time it is viewed by a browser because the server edits the page prior to sending it to the browser accordingly to what instructions the programmer has coded into that specific page. PHP was introduced in 1994. As of November 2007, it was installed on more than 21 million domains worldwide, and this number is growing rapidly. You can see the current number at http://www.php.net/usage.php PHP is an Open Source project. PHP originally stood for Personal Home Page and now stands for PHP Hypertext Preprocessor.