What is PHP
PHP was originally created by Rasmus Lerdorf in 1995. At that time PHP stands for Personal Home Page and now PHP stand for PHP: Hypertext Preprocessor, a recursive acronym.
PHP supports all the major databases like MySQL, Oracle, Generic ODBC,Informix,Sybase, Solid, PostgreSQL, etc
PHP has also attracted the development of many frameworks and cms that provide building blocks and a design structure to promote rapid application development (RAD).
Some of these frameworks include CakePHP, Symfony, CodeIgniter, Yii Framework and Zend Framework etc offering features similar to other web application frameworks.
Some of these cms include WordPress, Drupal, Joomla, Mambo, CMS Made Simple etc.
The PHP interpreter only executes PHP code within its delimiters. Anything outside its delimiters is not processed by.
In simple term PHP is a server-side scripting language, designed for dynamic Web pages.
Why php is popular
PHP is popular because it’s relatively easy to learn and relatively cheap to develop web projects.And in the other side, its a open source technology and development cost is lower than the other technologies like java and dot net.