"What n Why" of JQuery?

In this series of articles my aim is to make you start loving the Client Programming via JQuery.
To begin with, I am just trying to show you why JQuery is being used so widely.

What is JQuery? 

To put it in simple words, JQuery is nothing but a library of client side utilities, written on Javascript, to make client scripting an easy experience. 
Let's say you have a well in your village and you want to take some water out of it.
You traditionally do this by pulling a rope with bucket on the other end. But these days this can be done smartly by using a water pump too. So we can say that JQuery does the work of water pump for us.

Why JQuery?

The traditional Javascript programming always seemed to be complex and voluminous.  JQuery takes an edge on it because of the following reasons.

1. Very easy to use.
2. You can implement complex logic with few lines of code. 
3. It gives AJAX support too.
4. It can be used to create animations.
5. It provides you with some of the very useful widgets/controls for free like slider, spinner, progress bar etc. Also you can purchase or might get for free many other widgets/controls developed on JQuery as a base by thousands of developers across the globe.
6. Most important, it's free and open source. So you can get or develop many free/paid plugins too for fulfilling the business needs or for selling on the internet market.