Contributor(s): Ed Hannan and Sarah Wilson
This definition is part of our Essential Guide: A DevOps tutorial on migrating to microservices



REST technology is generally preferred to the more robust Simple Object Access Protocol (SOAP) technology because REST leverages less bandwidth, making it more suitable for internet usage. An API for a website is code that allows two software programs to communicate with each another. The API spells out the proper way for a developer to write a program requesting services from an operating system or other application.

This video by Kevin Babcock
details RESTful API design and
related HTTP concepts.

The REST used by browsers can be thought of as the language of the internet. With cloud use on the rise, APIs are emerging to expose web services. REST is a logical choice for building APIs that allow users to connect and interact with cloud services. RESTful APIs are used by such sites as Amazon, Google, LinkedIn and Twitter.

How RESTful APIs work

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


With REST, networked components are a resource you request access to -- a black box whose implementation details are unclear. The presumption is that all calls are stateless; nothing can be retained by the RESTful service between executions.

Because the calls are stateless, REST is useful in cloud applications. Stateless components can be freely redeployed if something fails, and they can scale to accommodate load changes. This is because any request can be directed to any instance of a component; there can be nothing saved that has to be remembered by the next transaction. That makes REST preferred for web use, but the RESTful model is also helpful in cloud services because binding to a service through an API is a matter of controlling how the URL is decoded. Cloud computing and microservices are almost certain to make RESTful API design the rule in the future.

This was last updated in December 2016

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What will future RESTful API models look like and how will they differ from current designs?
no one know the future. I wonder why people keep asking about the future and how will be the future of that or that ? did anyone traveler to the future and saw how will be ?
Love it!
Every company in the world needs an API in the close future. There will be no way out in order to get connected.

What is REST API in layman's terms? Why REST API preferable for the IoT implementation?



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