What is React Components?

React components are reusable, independent sections of code that define the structure, appearance, and behavior of UI elements in a React application. They allow developers to break down complex user interfaces into smaller, manageable pieces, promoting code reusability, maintainability, and testability. Components can be either functional components (using functions) or class components (using ES6 classes). They receive data as 'props' and render UI based on that data, allowing for dynamic and interactive user experiences. They are commonly used to build everything from simple buttons to complex web applications.