Functions In a Separate File
If your website contains a lot of pages, and you want your
jQuery functions to be easy
to maintain, you can put your
jQuery functions in a separate .js file.
Example
<head>
<script
src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js">
</script>
<script src="my_jquery_functions.js"></script>
</head>