A Colony is a type of settlement built for the purpose of creating a large civilisation. They are geared towards rapid expansion and where possible, terraforming. The main difference between a colony and Free Settlers are that the latter aren't interested in (or don't prioritise) growth.

Colonies can vary both in terms of size, and also in terms of why they were founded.

• Tiny - Less than a 10,000 people. A young colony, in an early stage of settlement and mostly consisting of first generation colonists.
• Small - Up to 100,000 people.
• Medium - Up to a million people, stable and consisting of mostly native colonists.
• Large - Up to ten million people, a thriving colony that is probably growing well and easily self-supporting.
• Huge - More than ten million people. Moving out of the realms of a colony into a full fledged civilisation. They will have a full economy by this point, capable of supporting high technology (TL 7+).

The colony size is a strong influence on the technology that the colony can support, but it's rare for any colony to be able to support a culture of TL 8 or above without a lot of outside support.

Corporate based colonies are the most common. A colony requires a large investment, and the investors are interested high rewards over the long term (hundreds of years or more). Rapid growth tends to be seen as critically important, and if this causes social issues then that's just too bad.