What a heads-up notification is
A heads-up notification is the floating banner that slides in at the top of your screen and sits above whatever you are doing — reading, watching, or playing a game. It is Android's way of saying “look now.” Incoming calls, alarms, timers, and turn-by-turn navigation all use it, along with any app set to the highest alert level.
What makes one appear
Heads-up banners show for notifications marked urgent or “make sound and pop on screen”. That level is controlled per app through notification channels (Android 8 and later). A routine email at “silent” importance will never pop; a ringing alarm or a repeat caller will. Some apps also request the banner directly for time-sensitive events.
Heads-up vs the notification shade
The heads-up banner is transient: it appears for a few seconds, then drops into the notification shade where it lives until you clear it. The shade entry is where you read and act later; the heads-up is only the momentary alert. If a banner vanishes before you read it, the information is usually still waiting in the shade — unless the app cancelled it.
How to stop heads-up pop-ups
To quiet a chatty app, open Settings → Notifications → [app] and lower its importance, or set the channel to Silent / Minimize. Do Not Disturb also suppresses heads-up banners except for your allowed exceptions. You can keep the app's information in the shade while stopping the interruptions.
When you need it to stay
A heads-up banner is built for the moment, not for things you must not lose. If an address, a code, or a reminder has to stay visible for minutes or hours, Dingpin pins it to the top of the shade so it is always there when you look.