1.1. Add structure to the header area using `<header role="banner">`

Mark up the main header section (i.e. logo, search field, etc.) with <header role="banner">.

Warning

While the <header> tag may be used several times in a web page, role="banner" must only be used once per web page.

It is perfectly acceptable to nest several ARIA roles:
<div role="search"> into <header role="banner">, for example.

<header role="banner">
   <img src="my-logo.png" alt="My website (logo)" />
   <div role="search" …>[…]</div>
   […]
</header>