jQuery: Introduction

What is JQuery? 

To be precise "A JavaScript library". 

jQuery is a very good and simple library which can be implemented to create a rich user interface simplifying the web 2.0 development. The jQuery event model is normalized to work across multiple browsers.

What are the features of jQuery?

• DOM element selections using the cross-browser open source selector engine Sizzle, a spin-off out of the jQuery project.
• DOM traversal and modification (including support for CSS 1-3)
• DOM manipulation based on CSS selectors that uses node elements name and node elements attributes (id and class) as criteria to build selectors
• Events
• Effects and animations
• Ajax
• Extensibility through plug-ins
• Utilities - such as user agent information, feature detection
• Compatibility methods that are natively available in modern browsers but need fallbacks for older ones - For example the inArray() and each() functions.
• Cross-browser support

Reference:  http://en.wikipedia.org/wiki/JQuery 

What are the available Libraries?

                jQuery UI

                jQuery AJAX

How jQuery works?

•   Include the reference to the the jQuery.js file.
•  Include the reference to the CSS file (if any; this comes up when we use the jQuery to design web pages.).
• Write the simple jQuery syntaxed JavaScript code to perform appropriate operation.

Reference: http://docs.jquery.com/How_jQuery_Works