jQuery's features break down accross eight major categories

# Core Functionality
Implement core jQuery functions as well as commonly used functions
# Selection and Traversal
Proving functions for finding content in documents and navigating among the content of the document

What is jQuery?

jQuery is great library for developing ajax based application. jQuery is great library for the JavaScript programmers, which simplifies the development of web 2.0 applications. You can use jQuery to develop cool web 2.0 applications. jQuery helps the programmers to keep code simple and concise. The jQuery library is designed to keep the things very simple and reusable.

jQuery library simplifies the process of traversal of HTML DOM tree. You can use jQuery to handle events, perform animation, and add the ajax support into your web applications with ease

#It is free, open JavaScript library
#Simplifies the task of creating highly responsive web page
#Work accross all modern browsers
#Abstract away browser-specific features, allowing you to concentrate on design
#Focusing on simplifying common scripting tasks
.Getting and manupulating page content
.Working with the modern browser event model
.Adding sophisticated effect