An ethnic group or ethnicity is a category of people who identify with each other, usually on the basis of a presumed common genealogy or ancestry or on similarities such as common language or dialect, history, society, culture or nation. Ethnicity is often used synonymously with the term nation, particularly in cases of ethnic nationalism, and is separate from but related to the concept of races.
Membership of an ethnic group tends to be defined by a shared cultural heritage, ancestry, origin myth, history, homeland, language or dialect, symbolic systems such as religion, mythology and ritual, cuisine, dressing style, art or physical appearance. By way of language shift, acculturation, adoption and religious conversion, it is sometimes possible for individuals or groups to leave one ethnic group and become part of another .
The largest ethnic groups in modern times comprise hundreds of millions of individuals , while the smallest are limited to a few dozen individuals .
