Patrick S thinks this is interesting: middleware is a function that accepts the request, response, and the next callbacks. The first two parameters represent the input and output of the middleware. The last one is a way to pass the flow to the next middleware in the list From Exploring middleware architecture from Node.js Blueprints by Krasimir Tsonev Publisher: Packt Publishing Released: June 2014 Note what is Middleware Share this highlight http://www.safaribooksonline.com/a/nodejs-blueprints/33653/ Twitter Facebook Google Plus Email Get Instant Access Now Start a Free Trial Learn about Safari for Business Have an account? Sign in. Minimise Unlock the rest of Node.js Blueprints and 30,000 other books and videos By clicking this box, you confirm that you have read and agree to the terms and conditions of our Membership Agreement, and you understand that when your trial period ends, you will be required to provide billing information if you wish to continue using the service. Unlock the rest of this book Start a Free 10-Day Trial loading Learn about Safari for Business Have an account? Sign in.