PHP is a recursive acronym for Hypertext Preprocessor. Its main focus is server side scripting which is specifically suited for web developers to write dynamic pages quickly.
PHP Manual – What is PHP?
How Does PHP Work?
When someone visits your PHP webpage, your web server processes the PHP code. It then determines which parts it needs to show to visitors. This includes content and pictures and hides file operations. Then translates your PHP into HTML. After it translates into HTML, this sends the webpage to your visitor’s web browser. This means that PHP is a powerful behind the scenes scripting language that your visitor’s wont see.