Question

What are

Answer 1

@e.mccormick

Answer 2

Well, did you look them up?

Answer 3

Yes, I did. But I still don't know what are they used for. And does a web page must have <header> and <footer>?

Answer 4

Not like they are absolutely needed. It is about trying to do some stanardized design layouts as part of HTML itself. Though, this is foolishness. People don't always put things in the places a standards body thinks they should go.

This talks about the intended use of them:
http://www.w3schools.com/html/html5_semantic_elements.asp

Answer 5

Great link! Thanks a lot!

Answer 6

np.

Answer 7

they are opening tags for headers(<header>) and footers(<footer>).

w3schools html 5