HTML

Question

How does the header work?

Answer 1

<header> basically "lifts" a few elements higher

Answer 2

It doesn't really work a special way. You make it work however you want to. It's basically just another div element. One of the benefits of adding extra "meaning" to a div (e. g. by using "header" instead) is it could have some SEO benefits (but since the more widely used search engines have proprietary algorithms, I'd take it with a grain of salt).