This is a group of people or nations or tribes or provinces that form an “alliance”. The agreement they make allows each member to control itself, but they agree to work together for common causes. Also known as a confederation or sometimes a league.

Canadian Confederation (French: Confédération canadienne) was the process by which the British colonies of Canada, Nova Scotia, and New Brunswick were united into one Dominion of Canada on July 1, 1867.

The Iroquois Confederacy (also known as a league or the original Five Nations). The Iroquois Confederacy, or Five Nations, was an alliance of five, later six, Nations—the Cayuga, Mohawk, Oneida, Onondaga, Seneca, and Tuscarora—located in modern-day New York state.

Note: By definition, the difference between a confederation/confederacy and a federation is that the membership of the member states in a confederation is voluntary, while the membership in a federation is not.

Iroquois Confederacy explained 
For details on how the Iroquois Confederacy worked see video by Historia Civilis: