System Tray
From MEPIS Documentation Wiki
System Tray -- is the portion usually on right hand side of the panel (Kicker) (it can be configured to be displayed in another place) that holds icons of different executing applications, these icons are used to either control the applications or to display notifications from those applications. E.g., one can use Pidgin icon in the System Tray to set the IM status ("offline", "online", "away", etc) and at the same time that icon is used to display notifications in case there is a new message received.
