Sometimes it[he]#039[/he]s useful to get visual feedback from a script. For example, when a script or cron job completes, a long-running build fails, or there is an urgent problem during script execution. Desktop applications can do this with popup notifications, but it can be done from a script too! You can use script commands to send yourself desktop notifications and reminders.

Source: LXer – Send desktop notifications and reminders from Linux terminal