add jquery to page
<!--You can insert Jquery into HTML with the <script> tag.-->
<head>
<script type = 'text/javascript' src = 'https://code.jquery.com/jquery-3.3.1.js'></script>
</head><!-- First either download, or use CDN and reference it -->
<!-- Here we grab it from a CDN -->
<script
src="https://code.jquery.com/jquery-3.4.1.js"
integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU="
crossorigin="anonymous"></script>
<!-- Lets say we have some <p>, with simple text
we give it an id -->
<p id="example">Hello, world</p>
<!-- We shall now play around with this element using jQuery -->
<script type="text/javascript">
// The vanilla way of accessing our example p element is
var e = document.getElementById('example');
// Then we would faff about with 'e'
// With jQuery we can get it like...
var ej = $('#example');
// jQuery has its own methods, instead of innerText and
// all those similar properties, we can do
$('#example').text("Goodbye everybody, I've got to go");
// Our example p element text will have changed :)
</script>