About jQuery

jQuery @ Wikipedia:

jQuery is a tool for working with JavaScript

jQuery is a cross-browser JavaScript library designed to simplify the client-side scripting of HTML.

jQuery is free, open source software.

jQuery’s syntax is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications. jQuery also provides capabilities for developers to create plugins on top of the JavaScript library. Using these facilities, developers are able to create abstractions for low-level interaction and animation, advanced effects and high-level, theme-able widgets. This contributes to the creation of powerful and dynamic web pages.