Dogs exist in a variety of shapes and sizes and many breeds have been developed as dogs have been selectively bred over the years to suit different purposes. However, essentially the dog is a hunting animal with strong predatory instincts. Drawings and paintings throughout the years show men hunting with dogs and dogs are still used today for hunting.

Dogs are highly intelligent animals, capable of learning, and this characteristic has enabled them to become a valuable part of the community acting as hearing dogs for the deaf, guide dogs for the blind, herding dogs, etc. The dog's highly developed sense of smell, whilst useful for hunting, has also been utilised by police forces and rescue organisations who use dogs to sniff out drugs and explosives, and to locate lost or injured people.

However, although dogs have many "uses" their most common place in the human community is as a companion animal. Intelligent, eager to please, loyal, friendly, protective, playful and a need to belong to a "pack" means that the dog is a family member in many households today.