The menu module provides an interface to control and customize Drupal's powerful menu system. Menus are a hierarchical collection of links, or menu items, used to navigate a website, and are positioned and displayed using Drupal's flexible block system. By default, three menus are created during installation: <em>Navigation</em>, <em>Primary links</em>, and <em>Secondary links</em>. The <em>Navigation</em> menu contains most links necessary for working with and navigating your site, and is often displayed in either the left or right sidebar. Most Drupal themes also provide support for <em>Primary links</em> and <em>Secondary links</em>, by displaying them in either the header or footer of each page. By default, <em>Primary links</em> and <em>Secondary links</em> contain no menu items but may be configured to contain custom menu items specific to your site.