jQuery is a JavaScript library that simplifies HTML DOM traversal and manipulation, as well as event handling, CSS animation, and Ajax. It is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications.jQuery is a JavaScript library that simplifies HTML DOM traversal and manipulation, as well as event handling, CSS animation, and Ajax. It is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications.jQuery is a JavaScript library that simplifies HTML DOM traversal and manipulation, as well as event handling, CSS animation, and Ajax. It is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications.