Successful use of Model View Controller (MVC) isolates the business logic from the user interface, resulting in an application which is easier to modify and manage the user interface or the business logic without affecting the other.

Model
Model represents the data for the application.

View
Renders the model in a human readable form called the User Interface

Controller
Holds the business logic that is responsbile for changing the data help in the model

In a typical web application, the the HTML pages (JSP/ASP) form the view, while the model is represented by the data stored in View State/Session/Database. Business Services are used to interact with the model and update the underlying data.

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