What are the features of Express?

express is a Node.js framework made to simplify developing web apps. Without express it must be used the Node.js native 'http' module, making quite verbose and complex the code needed to handle web request. Express lets the user to define routes, expressing HTTP verbs (get, post, ...) as function. Paths are defined as plain strings, supporting parameters as well. It makes possible to use middleware as well, an elegant way to create chain of functions added to the HTTP transaction (example of middleware are: authentication, managing payload formats like JSON and so on).