A totem is a stipulated ancestor of a group of people, such as a family, clan, lineage, or tribe.
Totems support larger groups than the individual person. In kinship and descent, if the apical ancestor of a clan is nonhuman, it is called a totem. Normally this belief is accompanied by a totemic myth.
Although the term is of Ojibwe origin in North America, totemistic beliefs are not limited to Native Americans. Similar totem-like beliefs have been historically present in societies throughout much of the world, including Africa, Asia, Australia, Eastern Europe, Western Europe, and the Arctic polar region.
In modern times, some single individuals, not otherwise involved in the practice of a tribal religion, have chosen to adopt a personal spirit animal helper, which has special meaning to them, and may refer to this as a totem.
Definition courtesy Wikipedia.