Float property question

Hi guys, I’m studying css and doing the lessons.
Currently here:

Floating elements are removed from the normal flow of a document and pushed to either the left or right of their containing parent element.

Can anyone tell me whats the parent element of this " "
I’m trying to understand exactly how it works in my mind, I understand the right id moving according to the left, but according to what does the left move? the header element h1? if yes, shouldn’t it be by default on top?

They don’t move in relation to each other, but to their containing element. In this case, both #left and #right are contained by the body element, so left will go to the left side of body, and right will go to the right side.

Oh, you’re absolutely right, thanks for clarifying it out, after looking at the code once again I noticed that the body element is in fact their parent element.