" The gold at the heart of MVC is the separation between the user interface code (the view, these days often called the presentation) and the domain logic (the model). The presentation classes contain only the logic needed to deal with the user interface. Domain objects contain no visual code but all the business logic. This separates two complicated parts of the program into pieces that are easier to modify. It also allows multiple presentations of the same business logic. Those experienced in working with objects use this separation instinctively, and it has proved its worth. "