Hi Deepthi,
your question is too descriptive and hard explain more about here.. but i give you small definition....
A repeatable or predefine solution for commonly occurred software problem.
framework design by developer which is made based on design
patterns and easy to use with any application...
like if we take example of Struts then you know Struts 1.3 there is front-controller which is heart of this framework now this front-controller work as controller so and every request comes front-controller first and then select business logic according to request and dispatch request to
jsp page.
So, Struts use two design patterns
MVC- Model view controller and
Front controller . So combination of design patterns make framework..