There are several different navigational page-type items in Sitecore.
Sections are top-level navigation items that appear in your site's main menu bar. Users cannot create, move, or delete Sections but may edit the item's fields.
Section Pages are second-tier navigation items that appear in the main menu's dropdown menus and as the primary items in the site's left nav. Users cannot create, move, or delete Section Pages but may edit the item's fields.
Basic Pages are third-tier and lower navigation items that users can create, move, edit, and delete.