Hound isn't one breed. It's a label for a big family of hunting dogs, including scent hounds like Beagles, Coonhounds and Foxhounds, and sighthounds like Greyhounds and Whippets. On adoption listings, it usually means a scent hound mix with long ears, a short coat and a loud voice. Adult weights range from about 20 to 70 pounds.
Most hounds are friendly, easygoing and happiest following their noses. That instinct means many howl, wander off after a scent and treat training as a negotiation. Short coats shed moderately and need little grooming. Because ancestry varies so much, size, energy and voice differ from dog to dog, so the label tells you less than how the dog actually behaves.