Page headers
Page headers are like miniature versions of the home page that sit atop each page
and do many of the things that home pages do, but in a limited space. Headers provide site identity and global navigation, with search and perhaps other tools. The exact location and arrangement of the components vary from site to site, but the overall design pattern has become fairly consistent.
Headers are the most visible component of site identity. What seems real is real: a collection of pages that share headers will be perceived as a “site” even if the pages originate from very different technical sources (php/Perl, jsp, .net, blog software, portal systems, SharePoint, web applications, content management systems, and so on).