is a specific kind of: social unit, unit.

is a broader term that covers: advocacy group, lobby, lobby group, pressure group, special-interest group, special interest, special interest group, third house | body politic, commonwealth, country, land, nation, res publica, state | Holy Roman Empire | union | Palestine Authority, Palestine National Authority, Palestinian National Authority | cadre, cell | amphictyony | lunatic fringe | revolutionary group.

is a member of: form of government, political system.