The neutral or relaxed posture is seen when dogs are in a comfortable situation such as at home.

The alert posture indicates interest.  It is a prelude to another behavior - either investigation, interaction, or a return to relaxation.

The offensive threat posture indicates a dog that is dangerous and ready to attack.  The tail may be wagging stiffly.  The nose is wrinkled, exposing the teeth, and the dog is usually vocalizing - a low throaty growl or bark.

The defensive threat posture also indicates a dog that is dangerous, but will attack only as a last resort.  He is frightened and may bite in self-protection if cornered.

Active submission is exhibited by a subordinate pack member to appease a dominant individual.  The submissive dog will avoid eye contact and may grovel and try to lick the mouth of the superior dog.

Passive submission is a more extreme form of submission, designed to turn off aggression from a more dominant dog.  The dog will be very still and may urinate.  Never continue to punish a dog that is showing passive submission.

When the dog is under stress, he lowers his posture and pants rapidly.  All learning stops.  If you see these signs, allow the dog to rest.

Play solicitation behavior includes the play bow with the front end lowered, a happy facial expression and wagging tail.  It is possible to imitate this posture and encourage the dog to play.