Routing is a core service available to any ASP.NET application. With routing, you can decouple site URLs from the physical locations of ASPX files. For MVC developers, routing is essential for mapping URLs to MVC controller action methods. This video covers the fundamentals of routing, touching on custom routes, generating route base URLs, and crafting useful URL constraints. You'll also see how the routing engine parses URLs into parameters and how to access that information in your code.