PHP (Hypertext Preprocessor) is a server-side programming language that is widely used for web development. It is a powerful and flexible language that is used to create dynamic and interactive websites.

One of the main benefits of PHP is that it is open-source and free to use, which makes it an attractive choice for developers. It is also easy to learn and has a large community of developers, so there is a wealth of resources and support available online.

PHP is used to build the backend of a website and is often used in combination with a database management system, such as MySQL. It is commonly used to manage user sessions, create custom web applications, and generate dynamic content.

PHP code is executed on the server, which means that it is not visible to users in the same way that HTML and CSS code is. This makes it a good choice for creating secure web applications, as the code is not visible to the user and can be used to process sensitive information.

In summary, PHP is a popular and versatile programming language that is widely used for web development. It is open-source, easy to learn, and has a large community of developers, making it a good choice for building dynamic and interactive websites.