Peace is a state of harmony characterized by the lack of violent conflict. Commonly understood as the absence of hostility, peace also suggests the existence of healthy or newly healed interpersonal or international relationships, prosperity in matters of social or economic welfare, the establishment of equality, and a working political order that serves the true interests of all. In international relations, peacetime is not only the absence of war or conflict, but also the presence of cultural and economic understanding .

From the Latin pax, meaning "freedom from civil disorder," the English word came into use in various personal greetings from c.1300 as a translation of the Hebrew shalom. Shalom, cognate with the Arabic "salaam", has multiple meanings: safety, welfare, prosperity, security, fortune, friendliness. The personalized meaning is reflected in a nonviolent lifestyle, which also describes a relationship between any people characterized by respect, justice and goodwill.

This later understanding of peace can also pertain to an individual's sense of himself or herself, as to be "at peace" with one's own mind attested in Europe from c.1200. The early English term is also used in the sense of "quiet", reflecting a calm, serene, and meditative approach to the family or group relationships that avoids quarreling and seeks tranquility — an absence of disturbance or agitation.

The domestic dog (Canis lupus familiaris), is a subspecies of the gray wolf (Canis lupus), a member of the Canidae family of the mammilian order Carnivora. The term "domestic dog" is generally used for both domesticated and feral varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in human history. The word "dog" may also mean the male of a canine species, as opposed to the word "bitch" for the female of the species.

The present lineage of dogs was domesticated from gray wolves about 15,000 years ago. Remains of domesticated dogs have been found in Siberia and Belgium from about 33,000 years ago. None of these early domestication lineages seem to have survived the Last Glacial Maximum. Although mDNA suggest a split between dogs and wolves around 100,000 years ago no specimens predate 33,000 years ago that are clearly morphologically domesticated dog.

Dogs' value to early human hunter-gatherers led to them quickly becoming ubiquitous across world cultures. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding handicapped individuals. This impact on human society has given them the nickname "Man's Best Friend" in the Western world. In some cultures, dogs are also source of meat. In 2001, there were estimated to be 400 million dogs in the world.