What does data=" " attribute do?

Question

<div data="group">

What does the 'data' attribute mean?

I'm using ThinkPHP framework so I'm guessing it might be related to it.

Answer 1

//Found this intresting article that describes it usages and examples
https://www.sitepoint.com/use-html5-data-attributes/

Answer 2

Thank you so much... I have searched but all I found is explaination regarding the "data-" attribute