JSPs are browser pages in HTML or XML. These pages contain Java code, which enables them to perform complex processing, conditionalize output, and communicate with other application objects. JSPs in Web Server are based on the JSP 2.1 specification.
In a Web Server application, you can call a JSP from a servlet to handle the user interaction output. Because JSPs have the same application environment access as any other application component, you can use a JSP as an interaction destination.
JSPs are made up of JSP elements and template data. Template data is anything not in the JSP specification, including text and HTML tags. For example, minimal JSP file requires no processing by the JSP engine and is a static HTML page.
Web Server compiles JSPs into HTTP servlets the first time they are called or they can be precompiled for better performance. This processing makes them available to the application environment as standard objects and enables them to be called from a client using a URL.
JSPs run inside the Web Server JSP engine, which is responsible for interpreting tags that are specific to JSP and performing the actions they specify in order to generate dynamic content. This content, along with any template data surrounding it, is assembled into an output page and is returned to the caller.