The header of a website refers to the top area of a web page in the frontend, which usually contains the logo, main navigation, and other important information. It is a central part of the website layout and provides users with quick access to essential functions.
For SEO, the header is important because it provides crawlers and search engines with important information about the website. The header can contain relevant keywords, metadata such as the page title or descriptions, and structured data that helps search engines index and rank the website.
For web crawlers, accessibility information is also in the header - but in the source code. The web crawler reads page title, metadata and meta robots tags in the header. The header element is marked as #header #!header.