PHP was suddenly the word on the street! well if you were a computer nerd it was. PHP or Hypertext PreProcessor is a client side language, that is, with both HTML and XHTML, your home computer requests the information from the server, and the server sends it, your browser then reads it, and displays it the way it see's fit. PHP is different, in that the server reads it, analyses it, then sends your computer the information according to the instructions in the PHP file, so your browser never get's to see everything. This is usefull in a few ways, it minimizes the amount of data, it gives you the programmer more control over how a page displays, and in some respects adds a little security.