Asp.net MVC is a framework that implements the Model-View-Controller pattern. The Model manages application data and logic, the View handles data presentation, and the Controller manages application flow and navigation. Asp.net MVC gives developers more control over HTML markup and supports unit testing. It uses a more logical and SEO-friendly URL structure compared to Asp.net Web Forms. When a request comes in, MVC routes it to a controller action, which accesses the model for data processing before passing the results to a view for rendering.