You can even extend jQuery itself by using plugins such as jQuery UI. This gives you a library of pre-written user interface interactions, effects, widgets and themes that you can tap into via JavaScript and jQuery. Basically, it does some really cool stuff and, instead of you having to write the difficult code, you just borrow it.
Typically to use JQuery UI, you download it and have it available within your web site folder structure. You then need to add a script link in your HTML document. For example,
<script src="jquery-ui/jquery-ui.js"></script>
If you had named the folder jquery-ui at the same level as the page you are working on, and the file jquery-ui.js is the name inside the folder. jQuery UI will only work on a hosted web server, not running off your local machine.
It will work with Trinket if you use this code:
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
or
http://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js
So, if we add these 3 lines of code to Trinket, both jquery and jqueryui will work
<link href="https://code.jquery.com/ui/1.12.1/themes/smoothness/jquery-ui.css" rel="stylesheet" type="text/css" />
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>