But struts internally uses servlets somewhere. While using struts technology you don't have to create servlets. It's job of struts itself. There are lot of clases in struts, some important are Action,ActionServlet, ActionForm,ActionErrors,ActionMessages,ActionError,ActionMessage
Bone up on MVC first (the model-view-controller design pattern). A Servlet is a controller. Struts has its own Servlet and builds on standard functionality to also provide view (as well as controller) .
The architecture of the portal UI is based on the Model-View-Control (MVC) design pattern. The MVC paradigm allows you to separate the code that handles business logic from the code that controls presentation and event handling.