Servlet and Jsp are both important.
Jsp is used for view.
Servlet is used for request.
It is used to exceute on the webbased,which is used to seperate the Dynamic and static Content.
It acts as a Controller in MVC .
It is a Java class implementing the javax.servlet.
Servlet interface that runs within a Web or application server's servlet engine, servicing client requests forwarded to it through the server.
JSP is a Presentation Layer.
A Java Server Page is a slightly more complicated beast.
The elements in a Java Server Page will generally be compiled by the JSP engine into a servlet, but the JSP specification only requires that the JSP page execution entity follow the Servlet Protocol.
Servlets and Java Server Pages are complementary APIs, both providing a means for generating dynamic Web content.
For read more information :http://www.roseindia.net/jsp/http://www.roseindia.net/servlets/