What if you wish to use other frameworks on your pages, while still using jQuery?
jQuery and Other JavaScript Frameworks
As you already know; jQuery uses the $ sign as a shortcut for jQuery.
There are many other popular JavaScript frameworks like: Angular, Backbone, Ember, Knockout, and more.
What if other JavaScript frameworks also use the $ sign as a shortcut?
If two different frameworks are using the same shortcut, one of them might stop working.
The jQuery team have already thought about this, and implemented the noConflict() method.