Most content within a site will not be listed in the primary navigation. Lists of faculty members, departments, or events will probably be listed in directories or views that are linked from the main navigation menu. If you are creating a node that will appear as a menu item in the primary navigation, you will need to modify the menu settings for that node. (Note: As a best practice, a site should never have more than seven links in the primary navigation, and a site should never have more than seven links as secondary items under a primary link.)

The ‘Title’ field in the menu settings is the text that will display in the navigation. This is required - even if it is a repeat of the node title.
The ‘Description’ will appear while a visitor hovers over the link and is optional.(See image above.)
The ‘Parent Item’ selection box shows what the parent link for this link will be. If this node will be a top-level navigation link, the Parent item should be ‘Primary links’. If this node will be a second-level navigation link under an existing Primary link, select the primary link under which the node should display. For example, if a site had About, Departments, Research, and Faculty as the top level links, each of those pages would have ‘Primary links’ selected as the Parent Item. If, under ‘About’, there were the links Services, News, People, then each of these nodes would have ‘About’ selected as the parent item.
The ‘Weight’ field defaults to 0. The weight determines the order in which the links will appear in the navigation. The links will appear in numerical order with the smallest numbers at the top. If all links have the same default weight (0), the links will be ordered alphabetically.