Is imperialism and an empire the same?

Imperialism and an empire are related concepts but not the same. Imperialism refers to the policy or practice of extending a nation's power and influence through colonization, military force, or other means, while an empire is the political entity that results from such expansion, often encompassing diverse territories and peoples under a single sovereign authority. In essence, imperialism is the strategy or ideology, whereas an empire is the outcome or structure that emerges from that strategy.