> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.ex2.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# What is PHP and what is it used for?

## The PHP script language

PHP (which stands for Hypertext Preprocessor) is an open-source script language. It is used in web development and is compatible for integration with [HTML language](https://help.ex2.com/en/article/what-is-the-html-language-1bqqpli/?bust=1784816900556). Several [content management systems (CMS)](https://help.ex2.com/en/article/what-is-a-content-management-system-or-cms-1c48kdh/?bust=1784816972500), such as WordPress, are built with PHP.

PHP is an integrated HTML language on the server side. Typically, developers use PHP to create dynamic content and databases. However, you can also use PHP to design entire applications.

Some of the world’s most popular websites and software are based on PHP. For example, Facebook was originally created using PHP, which is also at the heart of the popular WordPress CMS.

Almost 80% of all websites use PHP to some extent. This is one of the most popular programming languages in the world. 

Without being essential, knowing PHP language basics can help for the use and troubleshooting of WordPress. This is a very useful language in general for web developers.