React Native JS (Java Script) also known as React.js is a JavaScript library that is responsible for building a hierarchy of UI components or for rendering UI components. It also provides support to the front end and server side. It is a 1-12 months course and has 4 stages to become proficient in the react.
React native application
React native is an application that enables the development of real and exciting Android and iOS apps using the native UI elements. It helps in saving a lot of development time. Gained a lot of popularity by Facebook, react native now has a huge community support. Same code is used for creating the React Native iOS or React native Android apps and web development. You just need to know HTML, CSS, and JavaScript.