RESTful API

REST API

A RESTful API is an application program interface (API) that uses HTTP requests to GET, PUT, POST and DELETE data.

Representational state transfer (REST), which is used by browsers, can be thought of as the language of the Internet. Now that cloud usage is on the rise, various application programming interfaces (APIs) are emerging to expose Web services and REST is a logical choice for building APIs that allow end users to connect and interact with cloud services. RESTful APIs are used by many sites, including Google, Amazon, Twitter and LinkedIn.

A RESTful API breaks down a transaction to create a series of small modules, each of which addresses a particular underlying part of the transaction. This modularity provides developers with a lot of flexibility but can also be challenging for developers to design from scratch. Currently, the models provided by Amazon Simple Storage Service (S3), OpenStack Swift and Cloud Data Management Interface (CDMI) are most popular.

RESTful APIs explicitly take advantage of HTTP methodologies defined by the RFC 2616 protocol. They simply use "PUT" to change the state of or update a resource, which can be an object, file or block; "GET" to retrieve a resource; POST" to create that resource; and "DELETE" to remove it.