React (also known as React.js or ReactJS) is an open-source JavaScript library for building user interfaces or UI components. It is maintained by Facebook and a community of individual developers and companies. React can be used as a base in the development of single-page or mobile applications. However, React is only concerned with rendering data to the DOM, and so creating React applications usually requires the use of additional libraries for state management and routing. Redux and React Router are respective examples of such libraries.

React code is made of entities called components. Components can be rendered to a particular element in the DOM using the React DOM library. When rendering a component, one can pass in values that are known as "props.

Figuring out that a flexible, high-paying career as a web developer is the dream is the easy part. Where it gets harder is figuring out exactly what skills you need to land a job. If you’re planning on building websites for a living, you probably know you’ll need to learn coding languages like HTML, CSS, and JavaScript, but you’ll also notice developer job listings that call for less familiar skills..