Dog training is the process of teaching skills or behaviors to a dog. This can include teaching a dog to respond to certain commands, or helping the dog learn coping skills for stressful environments. Dog training often includes operant conditioning, classical conditioning, or non-associative learning to achieve the dog performing a desired behavior or skill. A person who trains dogs is said to be a dog trainer.
There are many methods of dog training and many objectives, from basic obedience training to specialized areas including law enforcement, military, search and rescue, hunting, working with livestock, assistance to people with disabilities, entertainment, dog sports, detection dogs and protecting people or property.
As pack animals, wild dogs have natural instincts that favor cooperation with their fellow dogs. Many domestic dogs, either through instinct or breeding, can correctly interpret and respond to signals given by a human handler.
Reference: Wikipedia Dog Training