The way it works is simple: React creates a virtual representation of the actual DOM (the real DOM tree), called a Virtual DOM. When a component’s state changes, React compares the virtual DOM with the real DOM to figure out what has changed. Then it updates the Real DOM in the least expensive way possible, without re-rendering the entire page. This improves web application speed and performance, allowing the developer to focus on what needs to be updated on the UI instead of thinking about how to update the DOM, which method to use and so forth.
React also supports server-side rendering, which makes applications faster and more reliable for websites. In addition, it’s easy to build cross-platform mobile apps with React Native, an open-source mobile app development framework for iOS and Android. The library is maintained by Meta (formerly Facebook), an independent software company, and it’s open-source, so the community is very active. This contributes to its high level of out-of-the-box functionality and extensibility.