An Auror, in the simplest terms, referred to a "Dark Wizard catcher": an Officer whose job it was to investigate crimes related to the Dark Arts and to hunt down and capture Dark Wizards. Once a criminal was apprehended, they were usually placed in custody while awaiting trial to answer for any crimes they committed. It was not uncommon for criminals to resist arrest, however; with some choosing to fight to the death rather than let themselves be captured, such as Death Eater Evan Rosier.^[4] Aurors could also call upon the support of trained trained Hit Wizards from the Magical Law Enforcement Squad when in need of backup.

Internally, Aurors are assigned to different tasks. Some, for instance, solved crimes and were something akin to detectives; looking into reports of illegal magical activity to track down suspects by questioning witnesses, examining evidence and following up on leads.^[5] An Auror in charge of an investigation was referred to as a 'Lead Auror' and received assistance from Investigative Assistants, lower-ranking Aurors charged with helping them with the investigation, and research assistants, whose job it is to compile and fact-check evidence for them.^[6]

Others seemed to act more like an intelligence agents, tasked with secretly tailing a specific target to monitor their activities, or else provide security services for high-profile places and high-risk targets, such as guarding Harry Potter,^[7] the Muggle Prime Minister^[8] or Hogwarts Castle in 1996, or patrol hidden and protected magical creature habitats in an attempt to ward off or capture wizard poachers trying to steal magical creatures to extract valuable bits and pieces from them for monetary gain, with poachers being such a common occurrence that most Aurors in Great Britain had run-ins with them throughout their careers.^[9] As of 1998, they also doubled as prison guards at Azkaban, working in shifts and rotating from the mainland.

By the 1990–1991 school year, veteran Auror Alastor Moody noted that while the amount of paperwork had increased noticeably from back when he first joined their ranks, he ultimately viewed it as a good thing, as it helped keeping the department "organised and honest"