Imperialism means a country with more power takes over a weaker country and pretty much just uses them for their resources. Most of the time the industrial revolution was a prior event that caused countries to participate in imperialism.
As you can see in this photo it is as if some countries could go out and just pick a spot on the world and claim it for their own and impose taxes and pay the people close to nothing for their own benefit.
One example would be when Great Britain took control of the 13 colonies and imposed all the taxes and fines.
The red in this picture is the British Empire and as you can see, where the 13 colonies would be the is red, along with the other almost half of the map.
Also, Hawaii was imperialized by America in the late 1800's. American boats where in the need of a fueling post in the pacific when they planned on starting the American-Spanish war. As a result, the Hawaiian islands were annexed or claimed as territory by the U.S. government and wasn't an actual state until 1959
Many countries have had their citizens shipped over as immigrants to work fields and that but the native area was known as the Kingdom of Hawaii when all the islands were finally put together until the overthrow of Queen Liliuokalani.
Another example was not only one country but many European countries that saw Africa as an opportunity to make money and tried to seize parts of it for resources. Britan, Germany, and France all participated in the Scramble for Africa.
Many other countries took bits and pieces of Africa but the need for raw material was so great that these countries had to participate with themselves and citizens so they could not make the goods and keep producing them without taking advantage of someone somewhere.