Model–View–Controller (MVC) is an architectural pattern used in software engineering. The pattern isolates "domain logic" (the application logic for the user) from input and presentation (GUI), permitting independent development, testing and maintenance of each.
An MVC application may be a collection of model/view/controller triplets, each responsible for a different UI element.
MVC is often seen in web applications where the view is the HTML or XHTML generated by the application. The controller receives GET or POST input and decides what to do with it, handing over to domain objects (i.e. the model) that contain the business rules and know how to carry out specific tasks such as processing a new subscription.
Model The model manages the behavior and data of the application domain, responds to requests for information about its state (usually from the view), and responds to instructions to change state (usually from the controller).
View The view manages the display of information.
Controller The controller interprets the mouse and keyboard inputs from the user, informing the model and/or the view to change as appropriate.
It is important to note that both the view and the controller depend on the model. However, the model depends on neither the view nor the controller. This is one the key benefits of the separation. This separation allows the model to be built and tested independent of the visual presentation. MVC separates the concern of storing, displaying, and updating data into three components that can be tested individually.