PHP is a server-side scripting language that is widely used for web development. It stands for Hypertext Preprocessor and is an open-source programming language that is easy to learn and use 123. PHP code is executed on the server, and the result is returned to the browser as plain HTML 1. PHP files can contain text, HTML, CSS, JavaScript, and PHP code 1. PHP can generate dynamic page content, create, open, read, write, delete, and close files on the server, collect form data, send and receive cookies, add, delete, modify data in your database, control user-access, and encrypt data 1. PHP is compatible with most web servers and operating systems, making it a versatile language for web development.