Javascript itself has long been a very useful tool, but writing cross-browser interactive code was often time consuming, and therefore expensive. The jQuery library is essentially a set of shortcuts enabling rapid development across all browser platforms. The animations and effects which can be achieved with jQuery also allow development on devices which do not support Adobe's Flash technology.

Query'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 plug-ins on top of the JavaScript library. This enables developers to create abstractions for low-level interaction and animation, advanced effects and high-level, theme-able widgets. The modular approach to the jQuery library allows the creation of powerful dynamic web pages and web applications.

jQuery provides a new paradigm for event handling in JavaScript beyond basic DOM element selection and manipulation. The event assignment and the event callback function definition are done in a single step in a single location in the code. jQuery also aims to incorporate other highly-used JavaScript functionality.