Hi,
Take your time to choose correct forum. There is another forum for Struts.
Read this
Carefully Choose One Forum
First of all you have to understand design
patterns. Design patterns is repeatable solution for commonly occurred software problems. Struts is framework and Struts basically developed using two design patterns.
1 ) MVC - Model view Controller.
2 ) Front controller.
so using framework you can make your application development fast and just stay far from some problems at the time of development.