MVC is one of the most common pattern or designs to build your project and to locate your code. So you split everything you code into this three parts:
- Model: This is your context or your class. Here you define and have your data
- View: This is your UI that shows the user what is going on.
- Controller: This controller will use the models to prepare your data and bring it to the view.
There are some examples that completely use the mvc-pattern like ASP.NET MVC for example. Here everything is prepared to work in a mvc-concept. I mean if you do not know the mvc-pattern, anyway you probably will code something like this because it is quit a way to code clean. In every project you think about where to put on the code. And most of the times you will separate the view and the controller and in every object-oriented-language you do something like classes. And hopefully you separate the classes and the controller as well … so there are not to many opportunities that are different to the mvc-pattern and are still clean and reasonable as well.