Question: Why do I need JSP technology if I
already have servlets?
Answer: JSP pages are compiled into servlets,
so theoretically you could write
servlets to support your web-based applications. However, JSP technology was
designed to simplify the process of creating pages by separating web
presentation from web content. In many applications, the response sent to the
client is a combination of template data and dynamically-generated data. In this
situation, it is much easier to work with JSP pages than to do everything with
servlets.
this
tip is based on SUN's FAQ's