PHP is a server site scripting language, and a powerful tool for making 
a dynamic web page. It was originally created by programmer Rasmus 
Lerdorf in the year 1994.
 
Some features of PHP are as follows:
PHP is an acronym for PHP: Hypertext Preprocessor.
PHP is widely-used, open-source scripting language.
PHP script are executed on server.
PHP is free to download.
PHP is a pretty widely used language and embedded in HTML.
PHP used to manage dynamic content, databases, session tracking even 
build entire e-commerce websites.

What can PHP do? / Why We Use PHP?

PHP  can build dynamic web-pages.
PHP can create open, read, write, delete and closed file on the server.
PHP can collect data in the database.
PHP can sent and receive cookies.
PHP can add, delete and modify data in your database.
PHP can used to control user-access.
PHP can encrypt data.

Why we used PHP?
PHP runs on various platform (Windows, Linux, Unix, Mac OS X etc.)
PHP support a wide range of database.
PHP is a compatible with almost all server todays.
PHP is free.