Ezeklin parents are the block tag that exists before the other , for example
div with id[a] is a parent to div[b] and div[b] is a child to div[a].. It can be any other tag apart from div
I think it works like this.
Html tag is the parent that contains 2 child tags head and body. The head tag is a child that is also a parent of the title tag, The title tag is a child of head tag but also has a grandparent which would be html tag.