Conventions of RESTful web services

RESTful web services are based on RESTful resources. A RESTful resource is an entity/resource that is mostly stored on a server and that client request using RESTful web services. Here are a few characteristics of a resource in terms of RESTful web services:

• It is an entity normally referred as a noun in the URL
• It is unique
• It has data associated with it
• It has at least one URI

If you are still wondering what exactly is a resource, consider the example of a blog. In a blog system, a Post, User, Category, or Comment can be a resource. In a shopping cart, a Product, Category, or an Order can be a resource. In fact, any entity which a client is requesting from the server is a resource.

Most commonly, there are five typical operations which can be performed on a resource:

• List
• Create
• Read
• Update
• Delete

For each operation, we need two things: the URI and HTTP method or verb.

The URI contains a resource name that is a noun and the HTTP method that is a verb. To perform some operation on an entity, we need to have a noun that tells us which entity we need to perform some operation. We also need to specify a verb to tell us what operation we want to perform.

For the preceding mentioned operations, there is a URL convention that we use with HTTP verbs and resource names. In the next section, we will review the URL structure and HTTP verbs for each operation.