The ID scanner was a device used by bounty hunters to identify potential targets.
The Mandalorian bounty hunter, Jango Fett had an ID Scanner attached to his helmet. When Jango was on a mission, his ally, Rozatta transmitted bounty information to the scanner, which allowed the scanner to identify bounties. When Jango scanned a bounty, his ID scanner displayed information about the bounty. The scanner provided information on the bounty's name, reward amount, gender, species, known affiliates, whether the bounty was wanted dead or alive, last known location, what the bounty was wanted for, and the name of the person or organization that posted the bounty.