A dog barks. Dog communication is about how dogs "speak" to each other, how they understand messages that humans send to them, and how humans can translate the ideas that dogs are trying to transmit. These communication behaviors include eye gaze, facial expression, vocalization, body posture (including movements of bodies and limbs) and gustatory communication (scents, pheromones and taste).
Humans communicate with dogs by using vocalization, hand signals and body posture. Dogs vary widely in shape, size and colors. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship and, more recently, aiding handicapped individuals and therapeutic roles.