Why does a closing tag have bag slash in the beginning at times, and at time at the end?

Question

Usage of Back Slash in closing tag

Answer 1

https://stackoverflow.com/questions/3558119/are-non-void-self-closing-tags-valid-in-html5?rq=1

Answer 2

It's not a backslash, it's just a normal slash (/). Sometimes, you don't need to put anything inside the element, therefore you don't need a closing tag; so the / will be at the end of the tag