jQuery is a fast, lightweight, and feature-rich JavaScript library that simplifies HTML document traversal, event handling, and animation. With its concise syntax and powerful set of functions, jQuery has become immensely popular among web developers for creating interactive and dynamic web pages. It provides an easy-to-use API that abstracts complex tasks, such as manipulating the DOM, making AJAX requests, and handling user interactions, into simple and intuitive methods. By allowing developers to write less code and achieve more functionality, jQuery has greatly contributed to the advancement of web development, enabling the creation of responsive and visually appealing websites across different platforms and browsers.