Imperialism is a policy that involves a ration extending its power by the acquisition of lands by purchase, diplomacy or military force. It is the policy of increasing the rule or authority of an empire or nation over foreign countries. Imperialism creates an unequal economic, cultural, and territorial division between classes, which often presents itself in the form of domination.
The primary goal of imperialism is to spread your beliefs to other countries. It is the domination of a weaker country by a more powerful force or nation. Its roots are in ancient Chinese history and extend up to and including World War II.