Ive also been a huge fan of jQuery for quite some time. I’ve been using jQuery for more than a decade now and I’ve enjoyed working with it.
In this case, the data- attribute is used to store a string like “something” or “this”. In the case of this element, jQuery stores that string in the element’s data on your page. The trick here is, you can also use jQuery to create elements that are entirely empty. If you use jQuery to create an empty element for an element, you can add it to a page with ajax (or with a script that runs in the browser).