JQuery is a cross-platform JavaScript library that helps simplify client-side scripting to better navigate documents, handle events, create animation and use Ajax.  It is frequently used in web application development given the feature-rich functionality and the fact that JQuery is a lightweight, free, integrates well into Visual Studio and is an open source library.  One of the key benefits of JQuery is that it focuses on manipulating the HTML DOM, which has become the most widely accepted practice of manipulating a Web page.  This means that the content will be shown even when JavaScript is disabled in the browser. In addition JQuery is SEO friendly and CSS3 compliant.