Admin is an ability in Among Us, which any player, including ghosts, can use to get information about other players' locations.
When in Admin (The Skeld, MIRA HQ and Polus) or Cockpit (The Airship), clicking the button next to the map will show what room everyone is in, anonymizing the players in yellow. The map updates when someone changes rooms but does not show exact positions. It also does not reveal location info for the corridors or Outside on Polus. Impostors that are in a vent and dead bodies are also shown on the map. It is mainly used to verify the location of a Crewmate or Impostor.
Lore-wise, it is implied that players' positions are known from their ID cards. The reason why their positions can't be traced out of specific areas is still unclear. Yet, it is hypothesized that the Admin ability uses some sensors hidden in specific areas to detect the number of players in rooms.
It is also unknown as to why exact identities cannot be traced.
When a Crewmate is killed, their icon will blink off momentarily. This can be effective against Impostors instantly reporting bodies that they just killed.