Expression Language (EL) is a scripting language used in web development to dynamically evaluate and manipulate data, such as variables, properties, or functions, that are stored in server-side or client-side contexts. Expression Language is used in various web technologies, such as JSP, JSF, or Struts, and can provide powerful features, such as conditional statements, iteration, conversion, or function calls, that can simplify and optimize the code of web applications. Expression Language can also improve the interoperability, reusability, and portability of web components, and can enhance the user experience and performance of web pages.