Imperialism, state policy, practice, or advocacy of extending power and dominion, especially by direct territorial possession or by gaining political and economic control of other areas. When it comes to Imperialism, historians use to distinguish in two different categories: Old imperialism and New imperialism.
Old Imperialism, European nations explored trade routes with the Far East, explored the New World and built settlements in North and South America as well as in Southeast Asia. They set up exchanging posts and gained spaces on the coasts of Africa and China, and worked jointly with the local rulers to ensure the protection of European economic interests. Their influence, however, was limited.
In the Age of New Imperialism that began in the 1870s, after the advent of the Industrial revolution (IR), European states established enormous empires mainly in Africa, but also in Asia and the Middle East.
We can see similarities between those two imperialism methods when we talk about the economic driving reasons, both before and after IR. Humanitarian and religious goals also con be pointed out. Other side effect was the confrontation and consequently destruction of native cultures.