What is PHP?
PHP, short for Hypertext Preprocessor, is an open-source, server-side scripting and programming language. The primary usage of it is for web development. However, PHP is a very important language for everybody involved in some way with WordPress. The reason for that is because PHP is used for the majority of the core WordPress software. Many people think that PHP as a programming language is not in use anymore, but actually, that is not quite true.