From The Art and Popular Culture Encyclopedia
In politics and in history, a colony is a territory under the immediate political control of a state. For colonies in antiquity, city-states would often found their own colonies. Some colonies were historically countries, while others were territories without definite statehood from their inception. The metropolitan state is the state that owns the colony. In Ancient Greece, the city that owned a colony was called the metropolis within its political organization. Mother country is a reference to the metropolitan state from the point of view of citizens who live in its colony. There is a United Nations list of Non-Self-Governing Territories.
A colony is mostly ruled by another state or can be run independently. Unlike a puppet state or satellite state, a colony has no independent international representation, and its top-level administration is under direct control of the metropolitan state.
The term "informal colony" is used by some historians to describe a country which is under the de facto control of another state, although this description is often contentious.