What is a Model-View-Controller (MVC) Paradigm in Salesforce Visualforce?

Hi Anurag,

Salesforce MVC is-

MODEL
The model is your database objects in Salesforce. The include the standard Salesforce objects like Leads, Contacts, Accounts, Opportunities etc but it also includes any custom objects you've created. Think of it like this - the "model" represents your data model in terms of MVC.

VIEW
The view represents the presentation of the data (i.e. the user interface).

Pages - While often just called "pages", what we are talking about is Visualforce pages. They are the building blocks of the user interface. Visualforce uses HTML to lay out the appearance of the application interface. Each page is referenced by a unique URL just like a regular webpage. The pages themselves also contain Visualforce Componentswhich can be invoked by simple tags inside the page.
Components - these are both standard and custom Visualforce Components. Think of them like widgets that you can add to your pages. Once you write the code once, you can reuse it on multiple pages. Components are important because they allow for this reuse. Components can be styled with CSS.
CONTROLLER
Controllers are the building blocks of the actual application logic. The controllers are written in Apex code and they end up controlling and enforcing all the business logic. Remember that one of the key design elements of MVC is to separate the logic from the UI. The presentation layer (the view) shouldn't be mixed with a bunch of business logic. Pages interact with the controller through components which shuttle the data and specifies what happens when the user actually interacts with the UI. Salesforce has pre-built controllers for many of the standard actions like View, Edit, Save. If you want to add new behavior though you can extend or build new controllers (custom controllers) in Apex.

Hi,

Salesforce MVC Pattern. Designed to divide software up into three interconnected parts so as to separate the internal representation of the data/information from the way in which it is presented and interacted to. In short - separate the user-interface from the business logic and the data itself.

Hope this helps.