Define a route

In the ASP.NET Web Forms application, every URL must match with a specific .aspx file.

ASP.NET introduced Routing to eliminate needs of mapping each URL with a physical file. Routing enable us to define URL pattern that maps to the request handler. This request handler can be a file or class. In ASP.NET Webform application, request handler is .aspx file and in MVC, it is Controller class and Action method.

public static void RegisterRoutes(RouteCollection routes)
{
    // attribute route
    routes.MapMvcAttributeRoutes();

    routes.MapRoute(
    "Default", // Route name
    "{controller}/{action}/{id}", // Route Pattern
        new
        {
            controller = "Home",
            action = "Index",
            id = UrlParameter.Optional
        }// Default values for above defined parameters
    );
}
protected void Application_Start()
{
    RegisterRoutes(RouteTable.Routes);
}