An API or Application Programming Interface is a software intermediary that lets in two applications to communicate with each other without having to know how they are implemented. Sometimes it is thought of as a contract, with documentation that represents an agreement between two parties. For example, each time when you use an app in the mobile like Facebook, it sends a message, or when you see the weather on your phone, these are the usage of an API.

React Native use the Fetch networking API to suit our needs. It simply calls the URL through Fetch, and then make requests to the server as needed. The React Native API mainly uses three lifecycle methods, which are constructor, componentDidMount, and Render.