What the always-on display shows
The always-on display (AOD) is the dim screen you see when the phone is locked but not fully off. It can show the clock, notification icons, and — depending on settings — a preview of incoming alerts.
How to control what shows
Open Settings → Lock screen → Always On Display (or Notifications on some models). You can choose to show notification icons only, show content, or hide notifications entirely on the AOD.
Hiding sensitive content
To keep things private, set lock-screen notifications to hide content. The AOD then shows an icon without the message text, so someone glancing at your phone sees you have a notification but not what it says.
Turning the AOD off
If the AOD drains battery or you prefer a black screen, set it to Off or Tap to show. Notifications then appear only after you wake the screen.
When the AOD is not enough
The AOD shows you have an alert; it does not keep that alert at the top once you are in the phone. Dingpin pins the notification you care about so it stays put in the shade until you clear it.