REST is an architectural pattern where two or more applications exchange resources among themselves through a set of operations on these resources. The resources are sets of data types that all the involved applications, such as products, customers, and so on, know about. For example, a client application can either ask a server application to give it a list of all the resources of a given kind that it stores, or ask the server to register a new instance of a given resource in its database. All such operations are communicated only by using the standard HTTP protocol, which makes the process both intuitive and easy to implement.

At the heart of the RESTful communication are the common HTTP verbs—GET, POST, PUT, and DELETE. In terms of the popular CRUD (Create/Read/Update/Delete) acronym, C corresponds to POST, R to GET, U to PUT, and finally D to, well, DELETE. If you are familiar with HTTP, you will already know that these verbs represent different request types sent...