A middleware is basically a function that will the receive the Request and Response objects , just like your route Handlers do. As a third argument you have another function which you should call once your middleware code completed.
Read moreDoes node js have middleware?
Typically all middlewares in nodejs/expressjs have access to request, response and next objects . A request is something that’s coming from a browser that invokes a particular function to perform certain tasks and return a response. “A particular function” in this case is a middleware.
Read more