jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
Sucuri is a cybersecurity company that provides website security solutions and services.