 To colonize means we just establish a colony. If we go to Mars, for example, and we establish a base over there, we can say it's a Mars colony. Colonialism, on the other hand, to colonialize is really an exercise in hegemony. It's a mode of domination. This is where a society might have existed for its own sake, but through the deployment of immense power, immense hegemony, you can turn it into something that doesn't exist for its own sake.