Administration Menus are the interfaces displayed in WordPress Administration. They allow you to add option pages for your plugin.
Top-Level Menus and Sub-Menus
The Top-level menus are rendered along the left side of the WordPress Administration. Each menu may contain a set of Sub-menus.
We recommend developers with a single option page to add it as Sub-menu to one of the existing Top-level menus; such as Settings or Tools.