Population

Population is the lifeblood of your empire. Without population, your colonies would sit idle, unable to perform even the most basic actions.

Population can exist in two forms: on a colony, and in cargo. Only population on a colony can do work for your empire or reproduce; population in cargo is considered to be in suspended animation. Note that colonies have both population storage and cargo storage. If a colony's population storage fills up, any excess population that appears on the colony, either via reproduction or cargo transfer, will be offloaded into the colony's cargo storage, where it will provide no additional bonuses to the colony. If space is freed up in the colony itself, then population will automatically be retrieved from cargo storage.

Population can come in a variety of races. Each empire has its own primary race, but you can capture (or trade for) population of other races. You may wish to do so in order to undome your colonies, or to take advantage of another race's traits and aptitudes - unlike in SE4, most traits and aptitudes stick with the race, even when the population is conquered, as opposed to being tied to the empire that owns the population.