Introducing middleware
The majority of you probably already know what middleware is, but some of you might not. Even if you have already been using ASP.NET Core for a while, you don't really need to know about middleware instances in detail, as they are mostly hidden behind nicely named extension methods such as UseMvc(), UseAuthentication(), UseDeveloperExceptionPage(), and so on. Every time you call a Use method in the Startup.cs file, in the Configure method, you'll implicitly use at least one – or maybe more – middleware components.
A middleware component is a piece of code that handles the request pipeline. Imagine the request pipeline as a huge tube where you can call something and then an echo comes back. The middleware is responsible for the creation of this echo – it manipulates the sound to enrich the information, handling the source sound, or handling the echo.
Middleware components are executed in the order in which they are configured...
