ASP.NET MVC uses the Routing middleware to match the URLs of incoming requests and map them to actions. Routes are defined in startup code or using attributes and describe how URL paths should be matched to actions. MVC also uses the same set of routes to generate URLs to include as links in responses.
This document will explain the interactions between MVC and routing, and how typical MVC applications make sure of routing features. See the for details on how to write more advanced routes.
In your Configure method you may see code like: