Hounds are dogs originally used for hunting. There are both scent and sight hounds. Scent hounds include the Beagle and Bloodhound, bred to follow prey using their noses. Sight hounds include Whippets and Greyhounds (a Lurcher is a crossbreed dog which is half sight hound) and have keen eyesight.
Whilst scent hounds can require significant amounts of exercise, some sight hounds are much more relaxed despite their capacity for high speed running, and will prefer short walks and a brief sprint every day.
Some more examples of Hounds are listed below, and you can visit the Irish Kennel Club website for more information. Please also remember that every dog is an individual and both genetic and environmental factors affect their temperament.