Routing is a mechanism in MVC that decides which action method of a controller class to execute. Without routing there's no way an action method can be mapped. to a request. Routing is a part of the MVC architecture so ASP.NET MVC supports routing by default

A route is a URL pattern that is mapped to a handler. The handler can be a physical file, such as an .aspx file in a Web Forms application. Routing module is responsible for mapping incoming browser requests to particular MVC controller actions.