Fundamentals Interview Questions

React is a JavaScript library for building user interfaces, particularly single-page applications. It allows developers to create reusable UI components and manage the application's state efficiently.

Components are the building blocks of a React application. They are reusable, independent pieces of UI that can be written as functions or classes, and they accept props as input to produce rendered HTML.

JSX (JavaScript XML) is a syntax extension for JavaScript used in React. It allows you to write HTML elements in JavaScript and place them in the DOM without using `createElement()` or `appendChild()`.

The virtual DOM is a lightweight copy of the real DOM that React uses to track changes. React updates the virtual DOM first and then efficiently updates the real DOM, minimizing direct manipulation and improving performance.