The Aurors are an elite group of witches and wizards who battle against the Dark Arts. They operate in some ways as soldiers but more often as intelligence agents, seeking out Dark Wizards and defeating them, often in fierce wizard duels. Alastor Moody and Frank Longbottom were famous Aurors. Aurors are sometimes refered to as Dark Wizard Catchers.

The Aurors were responsible for bringing to justice many of the Dark Wizards who supported Voldemort during the 1970s. They also battled the giants, killing many and driving the rest from Britain. Under the leadership of Bartemius Crouch Sr., the Head of the Department of Magical Law Enforcement after Voldemort's defeat, the Aurors were given sweeping powers. These powers allowed the Aurors to bypass the normal channels of justice and kill or capture enemy wizards using means nearly as vicious as those used by the Dark Wizards they fought. Sirius Black was imprisoned during this time without a trial because of these policies.

Some famous Aurors were Mad-Eye Moody and Frank Longbottom.

Barty Crouch Jr., in disguise as Moody, told Harry and Hermione that they had what it took to be Aurors (GF

Hit Wizards
The Department of Magical Law Enforcement maintains squads of trained Hit Wizards whose job it is to capture dangerous Wizard criminals. A group of these Hit Wizards captured Sirius Black after he supposedly killed Peter Pettigrew. The Hit Wizards are not the same as Aurors. Hit Wizards, it would seem, are sent primarily against criminals while Aurors track down and capture Dark Wizards.