What exactly does the "resettle" do to aliens in your colonies?

[hardcoregamer]

I am not sure what this policy does exactly. Its suppose to resettle the aliens, but where do they actually go? They don't leave their planet as far as I know.

Also, how do penal colonies work?

[Arakash]

I use the resettlement system a lot, its one of my favorite ways to micromanage late games.

Actually they do leave their planet if set on resettle, i use this frequently (even in non enslave empires) to keep hostile populations spread out in my empire, or away from their native empires.

Ill copy the section from the Galactopedia(not sure if this has been updated recently):

Resettle

Actively migrate these races away from the colony to other colonies that will accept them. Passenger ships will pick up these races from the colony.

If you have enabled the empire policy setting "Use Penal Colonies to implement Enslave policy" then these unwanted races will be migrated to Penal colonies for enslavement there.

Enslave

Enslaves these races, forcing them into hard labor. When a race is enslaved at a colony it’s growth rate will be zero.

For each race that you enslave, the corresponding empires of those races will take offense at your actions. The amount of offense is directly related to the population amount that you enslave.

Enslavement also provides a bonus to the colony's economy. The amount of the bonus depends on the proportion of the total population that is enslaved, up to a maximum of 50% if all of the population is enslaved.

If you have enabled the empire policy setting "Use Penal Colonies to implement Enslave policy" then some of your colonies will automatically be set as Penal Colonies (policy set to Enslave). Your other colonies with policy set to Resettle will migrate their unwanted races to the Penal colonies for enslavement.