Menu extra

A menu extra, menu item, menulet, or status item is a graphical control element in OS X. It is a small indicator that appears at the right of the menu bar. They often provide quick ways to use applications (e.g. iChat) or display information (for example the system clock), or control system-level variables (for example audio volume). There are a number of third-party menu items available. Menu extras are similar to items in the Microsoft Windows notification area but are less common.

There are many menu extras supplied with Mac OS X, many independent third-party menu extra applications, and many more supplied with 3rd-party products, most of which are installed from their parent application or system preferences pane, and may remain dormant until they are notified of an event (for example, Inkwell's menu extra will come and go when a graphics tablet is connected and disconnected). While OS X provides no centralized tool to enable or configure menu extras, some of them can be rearranged and dragged off the menubar while depressing the ⌘ key. Also, all Apple-supplied menu extras can be found in the folder /System/Library/CoreServices/Menu Extras.