In this article, we are discussing the fundamentals of JSP architecture and it's life cycle. In short, Java Server Pages(JSP) is a high level extension of servlet, which is used to deliver HTML and XML documents. Using JSP one can easily embed Java Codes into HTML Pages.
Also if we look at the functionality, JSP code get translated into servlets at runtime by the JSP engine, which is chached and reused until the orignal JSP Servlet Code is modified by the programmer.
JSPPage and HttpJspPage are the interfaces that is defined into 'javax.servlet.jsp' package that contains the life cycle methods of complied JSP Page.
jspInit(), jspDestroy() and _jspService(HttpServletRequest request,HttpServletResponse response) are the life cycle methods of the compiled JSP page.
Diagram of JSP Architecture:
Recommend the tutorial