Officially PHP stands for PHP: Hypertext Preprocessor which is a server-side scripting language, open source and widely used.
You are allowed to build dynamic websites with the help of PHP. You can run PHP on any platform whether it is UNIX, Linux and windows. You are able to run PHP code on your home computer which has windows and then run the same code on a Unix/Linux Server. It can run virtually on any platforms. It is the most widely used scripting language for server-sided web development. You can do various things by using PHP such as:
Create authentication page
Validate forms input
And many more
Some reasons that make PHP most efficient server side scripting language:
Easy to start with
Everyone is curious about how to learn PHP. You have to add a few PHP-tags with e.g. a for-loop in its existing HTML-files and then upload it to the server and the result or the error message will be displayed. Associative arrays and Dynamic typing makes it easier to start using PHP.
Easy to use
PHP doesn’t require any compilation as compared to many solutions such as Java. It is very easy to use you have to write only the script and then upload it to the server and then update the browser.
Integrated database support
PHP provides support for the most popular databases like e.g. MySQL that means it is easy to start using databases; there is no need to install additional drivers. The easy to use web based admin tool PHPMyAdmin is very important to the PHP's success in combination with MySQL.
Old language (since 1995) with a big user base
PHP was designed by Rasmus Lerdorf in 1994 but appeared in 1995 for web programming. Since then the user base has grown and now there are many web-oriented libraries and frameworks are available. Some examples are e-shopping and blog shopping-platforms.
With the ability of PHP doing work on both Linux and Windows there is no problem to find hosting with PHP pre-installed.