PHP (Hypertext Preprocessor) is a server-side scripting language and a powerful tool for making dynamic and interactive web pages. It is the most popular scripting language on the web and is used to create websites, web applications, and dynamic content. PHP isopen source, which means it is free to download and use. It is also highly flexible and can be used for a variety of tasks, from small websites to large, complex web applications.PHP works by first processing a file called a script, which contains instructions written in the PHP language. The script is then read by the server and the instructions are executed. This allows the user to quickly create dynamic pages and to access databases, such as MySQL, to store and retrieve data. PHP can also be used to create forms, handle cookies, and generate images.PHP is used to create websites and web applications, such as online shopping carts, forums, content management systems, and more. It is especially popular for its ease of use and ability to quickly and easily create dynamic content. Many of the most popular websites and applications, such as Facebook, WordPress, and Twitter, are written in PHP. PHP is also used to create web services, which allow different websites to communicate with one another.PHP is also a popular language for creating mobile applications, such as iOS and Android apps. It is easy to learn, and many developers have experience with the language, which makes it an attractive option for creating mobile applications.Overall, PHP is a powerful language that can be used to create dynamic, interactive web pages and applications. It is a popular choice for developers due to its flexibility, ease of use, and a large community of experienced developers.