Using OWIN middleware with IIS web server

OWIN stands for "Open Web Server Interface for .NET" and it defines a standard interface between .NET web servers and web applications. This, OWIN sits between a web server, such as IIS, and then allows your .NET web application to talk to the web server through the OWIN implementation, like this:

IIS -- OWIN -- ASP.NET

There are plenty of details you need to understand when working with OWIN, especially if you want to use more advanced features like claims-based authentication, JWT tokens, web sockets, and so on. Luckily, Microsoft has written a nice article talking about making OWIN working together with IIS web server.