React

React (also known as React.js or React.JS) is a free and open-source front-end JavaScript library for building user interfaces based on components. It is maintained by Meta (formerly Facebook) and a community of individual developers and companies.

React was first released in May 2013. It was created by Jordan Walke, a software engineer at Facebook, who was influenced by an earlier library called XHP.

Overview

React allows developers to create large web applications that can change data without reloading the page. Its main goals are to be efficient, declarative, and flexible. It focuses solely on the view layer of an application, meaning it handles rendering the user interface, while other concerns such as routing and data management are typically handled by additional libraries.

Key Concepts

• Components — Independent, reusable pieces of code that return a piece of user interface.
• Virtual DOM — An in-memory representation of the real Document Object Model (DOM), which React uses to determine the most efficient way to update the browser.
• JSX — A syntax extension that allows developers to write HTML-like code within JavaScript.
• State — Data that changes over time within a component.
• Props — Short for "properties," used to pass data from parent components to child components.

History

• 2011 — Deployed on Facebook's newsfeed.
• 2012 — Deployed on Instagram.
• May 2013 — Open-sourced at the JSConf US conference.
• 2015 — React Native released, extending React's component-based approach to mobile app development for iOS and Android.
• 2017 — React 16 released, introducing a new internal architecture known as Fiber.

Usage

React is widely used for developing single-page applications and mobile applications. It is used by numerous large-scale organizations, including Meta, Netflix, Airbnb, and Uber. It also serves as the underlying foundation for popular frameworks such as Next.js and Gatsby.