Middleware is defined in the OWIN (Open Web Interface for .Net) specification as pass through components that form a pipeline between a server and application to inspect, route, or modify request and response messages for a specific purpose. Middleware consists of application components are incorporated into the ASP.NET HTTP pipeline. The text is in the ASP .Net Core documentation, and as can be seen, with middleware we can insert a component that is incorporated in ASP.NET HTTP pipeline, that is, we can develop a code with a purpose to manipulate the requests and responses.

A normal for middleware is that regularly there will a chain of middleware whereby request of arrangement, one is called after the finish of other and the current middleware can on any minute wipe out conjuring the following middleware, in this manner all chains of the middleware will be scratched off.