API stands for Application Programming Interface which allows software applications to communicate with each other via API calls. API is a defined set of rules, which contains clearly defined methods of communication. Postman is an application for testing APIs, by sending request to the web server and getting the response back. It allows users to set up all the headers and cookies the API expects and checks the response. It is a great tool when trying to dissect RESTful APIs made by others or test ones you have made yourself. It offers a sleek user interface with which to make HTML requests, without the hassle of writing a bunch of code just to test an API’s functionality.