A hound is a breed of dog that is mostly trained to assist hunters in keeping track of and chasing their prey in the wild. People often contract hound dogs with gun dogs, adept at identifying the exact location of their prey, and with retrievers, trained to recover items and give it back to its master.

There are three types of hound dogs.
Sight hound ? A sight hound is a type of hound dog which uses great speed to be able to catch up and keep track of its prey. These dogs are much capable of killing game by themselves.
Scent hound ? A scent hound finds its prey by following its scent. Scent hounds have great endurance, but lack the speed of a sight hound.
Other ? These hound dogs follow prey by both scent and sight. Breeds in this category are much difficult to classify.

In law enforcement, some hound breeds are used to track down missing persons and escape prisoners. The majority of hound dogs used in these operations are scent hounds. Sometimes scent hounds are used to sniff luggage in airports to check for illegal substances being brought in or out of the country.

Sight hounds are more suited for big game hunting.