Java servlets are server-side Java programs that can be used to generate dynamic content in response to client requests in much the same way as CGI programs. Servlets are accessed through URL invocation.
You create servlets using the Java Servlets API. Sun Java System Web Server 6.1 includes all of the files necessary for developing and running Java servlets. You can compile servlets using any Java compiler you like, as long as the webserv-ext.jar file is accessible to your Java compiler. The webserv-ext.jar file is in the server installation directory at:
A JSP page is a page that can be viewed in a web browser, much like an HTML page. However, in addition to HTML tags, it can include a set of JSP tags and directives intermixed with Java code that extend the ability of the web page designer to incorporate dynamic content in a page. These additional features provide functionality such as displaying property values and using simple conditionals.
For more information about creating web applications that use servlets and JSPs on Sun Java System Web Server 6.1, see the Sun Java System Web Server 6.1 SP9 Programmer’s Guide to Web Applications.