The Model-View-Controller Architecture

The MVC architecture comprises three layers, each with unique and independent responsibilities:

Model
       Represents the core business/domain data and logic, typically with POCOs (Plain Old CLR Objects), devoid of technology-specific implementations

View
       Responsible for transforming a Model or Models into a response sent to the user (typically HTML)

Controller 
       Interprets incoming web requests, managing the interaction between the user and the model (typically through database queries, web services calls, etc.) and building a Model for the View to consume
   
       In the course of an ASP.NET MVC website request, the platform locates and executes the  corresponding controller method, also called the action. The result of this action is almost always an ActionResult. The most widely used type is the ViewResult—an ActionResult indicating which view the framework should respond to the request with. Following ASP.NET MVC’s strict separation of concerns, it is not the controller that is responsible for rendering HTML. Instead, the ASP.NET MVC framework passes the ActionResult from the controller to the View Engine, which handles the conversion of a ViewResult into rendered HTML to send back to the client.