Colonialism: The policy or practice by which one country extends its control over another territory or people for economic exploitation or political gain.
Empire: A group of territories or nations under a single supreme authority, often led by an emperor or empress. Spain had a vast empire during its colonial period.
Treaty of Tordesillas: A treaty signed between Spain and Portugal in 1494 that divided newly discovered lands outside Europe between them along an imaginary line. It aimed to prevent conflicts over colonization efforts.