The MVC Design Pattern

MVC stands for model-view-controller. It is a software architecture pattern used heavily in Cocoa (macosx && iOS) Applications.

From the Apple docs:

"The Model-View-Controller (MVC) design pattern assigns objects in an application one of three roles: model, view, or controller. The pattern defines not only the roles objects play in the application, it defines the way objects communicate with each other."

"Model objects encapsulate the data specific to an application and define the logic and computation that manipulate and process that data."

"A view object is an object in an application that users can see. A view object knows how to draw itself and can respond to user actions. A major purpose of view objects is to display data from the application’s model objects and to enable the editing of that data."

"A controller object acts as an intermediary between one or more of an application’s view objects and one or more of its model objects. Controller objects are thus a conduit through which view objects learn about changes in model objects and vice versa."

From Wikipedia