These links are related to the global navigation, but instead of providing links to major web sections (as the global navigation section does), global links point to important pages that should be accessible from anywhere in the site. Typical candidates for global links are contact us, site map, search, etc.
These links are sometimes found in the very top right of the page. Global links are an optional element; they are not required, but may be useful depending on the size and structure of your site.