This diagram from the article I linked to describes MVC at its simplest:
A request is sent to a servlet which serves as the controller (the C in MVC).
This interacts with the Model (the M in MVC) which fetches information from the DB and puts it into appropriate classes (usually beans) for passing back to the controller.
The bean(s) are sent to a
JSP view (the V in MVC) as scoped variables via a forward, and the generated HTML page is sent as the response.
Further refinements are needed for industrial-stregth apps (separation of task and page controllers, additions of front controller and so on), but the above is a good starting point for MVC web apps.