JSP, or Java Server Pages, is a server-side include language based upon the Java servlet specification.
JSP or JavaServer? Pages is a Java technology that allows developers to integrate programming within HTML, XML or other types of web pages. The technology allows Java code and certain pre-defined actions to be embedded into web pages. As such, it is considered a sort of server-side include.
JSP files are compiled into Servlets by a JSP compiler. A JSP compiler may generate a servlet in Java code that is then compiled by the Java compiler, or it may generate byte code for the servlet directly. In either case, it is helpful to understand how the JSP compiler transforms the page into a Java servlet. For an example, see the following input, and its resulting generated Java servlet.