Hound isn't one breed but a label for a big family of hunting dogs. Scent hounds such as Beagles, Coonhounds and Foxhounds follow a trail with their noses, while sighthounds such as Greyhounds and Whippets chase what they see. On adoption listings, hound usually means a scent hound mix with long ears, a short coat and a big voice.
Most are friendly with people and other dogs, and happiest with their noses to the ground. They can also howl, wander off after a scent and treat training as a negotiation. Because ancestry varies so much, size, energy and voice differ a lot from one hound to the next, so the details in each listing say more than the label. The short coat sheds moderately and is easy to keep up.