what is a header for?

Answer 1

The <header> element represents a container for introductory content or a set of navigational links.

A <header> element typically contains:

one or more heading elements (<h1> - <h6>)
logo or icon
authorship information

You can have several <header> elements in one document.

Note: A <header> tag cannot be placed within a <footer>, <address> or another <header> element.

Answer 2

the best answer

Answer 3

<h1>