PHP, originally standing for Personal Home Page and now known as Hypertext Preprocessor, is a server-side scripting language widely used for web development. PHP scripts are executed on the server, allowing for dynamic content generation, database interaction, and session management. PHP is embedded in HTML and is known for its ease of use, extensive libraries, and compatibility with popular databases like MySQL. As an open-source language, PHP powers many websites, including content management systems like WordPress. Its ability to generate dynamic content makes it an integral part of building interactive and responsive web applications.