The header.php file displays the site’s header content. In Starkers, the DOCTYPE used is for HTML5.
Following is a description of the contents of the header.php file in the theme:
The header.php file displays all of the head section for the web page up to the div for the main content “<div id=”main”>”. Here is where the required style.css file is called for the web page, by using the php bloginfo function “stylesheet_url”. One of the last things included in the head section is the call to wp_head(), a hook used to add elements like styles, scripts and meta tags.
The body is given a class by calling the php function body_class(). After that, the title and description of the web site are displayed. Then follows logic to allow those using screen readers and text browsers to skip past the display of the main menu.