What Is PHP?

PHP Points                       
      *PHP stands for PHP:Hypertext Preprocessor
      *PHP is  a server-side scripting language,like ASP. 
      *PHP scripts are executed on the server 
      *PHP supports many databases                                                 
     (MySQL,Informix,Oracle,Sybase,Solid,PostgreSQL,Generic ODBC,etc.)
      *PHP is an open source software.
      *PHP is free to download and use.

What is PHP File? 

       *PHP files can contain text ,HTML tags and script
       *PHP files are returned to the browser as plain HTML  
       *PHP files have a file extension of  
       ".php",".php3", or ".phtml"