PHP is a scripting language often used for web-development. It is often used for server side development and is used for creating fast, efficient, dynamic and interactive websites.

PHP is easy to learn and use. And is freely available. It is the main and favorite language of lot of open source projects especially for web-development. Its syntax is very much similar to perl and C and is often used with Apache (web-server) and Mysql (database). The combination of Apache, PHP and Mysql is available as a stack in an open source tool called LAMPP and is used world wide for web-application developments, including a lot of commercial applications.