Device Announcement refers to a feature in Android operating system that allows users to customize and control notifications for their devices. This includes setting up different sounds, vibrations or visual indicators for various types of alerts such as incoming calls, text messages, calendar events, alarms etc. Users can also choose the priority level of each notification and decide whether they want it to appear on the lock screen or not. In essence, device announcements allow users to personalize their experience with their devices by setting up specific preferences for different types of notifications.