An example of social groups.

Types of social groups
In terms of numbers, small averages and
big. Small (2-3, up to 20-30 people) who know each other well. Examples: family, school class, aircraft crew, company of friends. Average (examples) work collective, residents of the yard, street of the district, settlement. Large (examples) nauia, national coass strata.
By the nature of the relationship: primary and secondary. Primary (small groups: a group of friends, peers, neighbors) Secondary (medium and large groups: industrial and economic organizations, trade unions, political parties)
By the fact of existence: nominal (social category) and real. Nominal (bought washing powder, living in separate communal apartments). Real (man, woman, Russians, children)
By the way of organizing and regulating interaction: formal (official) and non-formal (not official). Formal (school class, sports team) Informal (poetry circle)
By social status: ethnic, territorial, demographic, professional, confessional. Ethnic (tribe, nation, nationality, race). Territorial (Gorazhan, villagers). Demographic (men, women, children, parents, young people). Professional (teachers, doctors, lawyers, agronomists). Confessional (Christian, Buddhist, Muslim)