An Action is an adapter between the contents of an incoming HTTP request and the corresponding business logic that should be executed to process this request.
Action classes act as the controller in the MVC pattern. Action classes respond to a user action, execute business logic (or call upon other classes to do that), and then return a result that tells Struts what view to render.
One of the most common responsibilities of the Action class is to process user input on a form and then make the result of the processing available to the view page. When the form is submitted, Struts will call any set methods of the Action class that match the form field names.
