ASP.NET is a web development platform that provides the necessary tools and infrastructure to build robust web applications for desktops and mobile devices. It uses HTTP to facilitate communication between the browser and server. ASP.NET code is compiled and written using the reusable components in the .NET framework. ASP.NET web forms extend the event-driven model to web applications by allowing servers to process user interactions and maintain state across page requests. The ASP.NET runtime transforms pages into classes to represent them as objects along with any server controls.