why would you use a cdn to host jquery files code example

Example 1: jquery growl cdn

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js" type="text/javascript"></script>
<script src="javascript/jquery.growl.js" type="text/javascript"></script>
<link href="stylesheets/jquery.growl.css" rel="stylesheet" type="text/css" />

Example 2: how to start using jQuery CDN

<script
  src="https://code.jquery.com/jquery-3.4.1.js"
  integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU="
  crossorigin="anonymous"
></script>