Pop-up notification

Close-up of the upper right corner of a Lubuntu 12.04 desktop, showing a notification that informs the user that the battery has finished charging
Close-up of the upper right corner of a Windows 8 desktop, showing a notification that informs the user that a new removable drive is now attached

The pop-up notification (or toast, passive pop-up, snackbar, desktop notification, notification bubble, or simply notification) is a graphical control element that communicates certain events to the user without forcing them to react to this notification immediately, unlike conventional pop-up windows. Desktop notifications usually disappear automatically after a short amount of time. Often their content is then stored in some widget that allows the users to access past notifications at a more convenient time.

On mobile devices, a push notification system is typically used.