JavaScript is an object-oriented, cross-platform scripting language widely used to control dynamic components on Web pages. JavaScript is often used for executing code on a Web page when events are triggered, such as the mouse moving over a page element, or a form being submitted. This code can manipulate variables as well as page elements allowing animated text, popup windows, and form validation.

Whether the JavaScript code can be run properly depends on which browser the page is being viewed with, and whether they have JavaScript enabled, although all the popular version 4+ browsers support it.

jQuery is a lightweight JavaScript library that emphasizes interaction between JavaScript and HTML. jQuery is free and open source software. It exists as a single JavaScript file, containing all the common DOM, Events, Effects, and AJAX functions.

JQuery, a popular open source JavaScript Library, provides many advanced and cross-browser functions that can enhance your web applications. It removes the headaches of cross platform Javascript compatibilities. It is very easy to use as compared to other JavaScript libraries and JavaScript as well. It has a large set of library/functions. jQuery has good documentation and help manuals are easily available. jQuery supports AJAX functionality.