Understanding how dogs communicate is important while building a relationship with them. Domestic dogs are social animals and have developed a variety of ways to communicate with each other as well as with other animals. Communication can take place through subtle dog postures as well as not-so-subtle vocalizations.
One important way through which dogs communicate with each other is through something known as 'Calming Signals'. Introduced by acclaimed Norwegian dog trainer Turid Rugaas in her book "On Talking Terms with Dogs: Calming Signals", these are dog postures or behaviours used in social interactions, particularly the ones where the dog is feeling uncomfortable or threatened. Rugaas hypothesized that the use of calming signals tends to lower the probability that another dog will act aggressively toward the dog doing the signalling.