There is a comprehensive confusion around these concepts, in some cases, they are even used as synonyms, that’s why now we are going to clarify them.


An Application Programming Interface, or API, in practical terms, is the way two systems communicate with each other, for instance, when you sing up into a new website using your existing Facebook credentials. An API also can be described as an endpoint of a system that allows the use of some of its functionalities from another system.

If you want to capture photos or video from the iPhone’s camera, you don’t have to write your own camera interface. You use the camera API to embed the iPhone’s built-in camera in your app

Chris Hoffman1Chris Hoffman. 2018. What Is an API?.


REST stands for Representational State Transfer and it refers to an architectural style for development that provides a standard between web systems2codecademy. What is REST?. The strong point of the REST architecture is to have the client and the server as two separate entities, this allows changes in both systems without any communication conflict.

As codecademy points out3codecademy. What is REST?, as long as each side knows the format of the message, they can be separated in a modular way improving the flexibility of the system.

To learn more about the REST architecture you can check out restfulapi’s guidelines4restfulapi. Guiding Principles of REST.


A REST API Is no more than an API that implements the REST architecture. Moreover, RESTful is basically a synonym of REST API, as Latinovic Milan5Latinovic Milan. REST API tutorial – What is API? REST vs RESTful? says: “(RESTful) is usually used to describe web services which implement REST architecture.”

📍 Postman

As an extra point, we can mention postman, a free software with a graphic interface used to develop and debug APIs. Its multiple functionalities and features can make your work-flow a lot easier.