PHP is a server-side scripting language designed for web development but also used as a general-purpose programming language. Originally created by Rasmus Lerdorf in 1994, the PHP reference implementation is now produced by The PHP Group.
PHP is a widely-used, free, and efficient alternative to competitors such as Microsoft’s ASP.
Working with wordpress you can build complex websites with PHP allowing you to access the site yourself.
History of PHP
PHP was created sometime in 1994 by Rasmus Lerdorf. During mid 1997, PHP development entered the hands of other contributors. Two of them, Zeev Suraski and Andi Gutmans, rewrote the parser from scratch to create PHP version 3 (PHP3)
our servers use it - currently on version 5 and above.
Usage of PHP
As of January 2013 , PHP was installed on more than 240 million websites (39% of those sampled) and 2.1 million web servers.
Now PHP is used by 79.8% of all websites where the server technology is known. The next closest competitor is ASP.Net at 19.8%.
Flexibility or Compatibility of PHP
PHP is the most widely-used, open-source and general purpose scripting language. PHP code could be used in query database and also to create images, you can read and edit files. In PHP the output of the code is the combination of HTML script. PHP is flexible/compatible to use in almost all operating system.
Server side code?
Server Side is the what allows us to more accurately control your site - instead of needing a developer to constantly update your site we can build complex systems that allow a client to change the site themselves.
PHP is the backbone that holds all the other parts together allowing for complex functions to run before pages load so that a user has access to content specific to them. It's what people generally use for Logins systems.
Even the greats use it
Some of the biggest online brands, such as Facebook, ProProfs, Digg, Friendster, Flickr, Technorati, and Yahoo! are powered by PHP.