Many countries wanted to control over many economic activities in other countries as well as utilize other countries for cheap labor. In addition, some countries wanted to explore the world and conquer for their homeland while other countries thought that their own country and race was superior to all other countries and therefore believed it was needed that they invade other countries and educate them as well as some countries practicing imperialism to convert people to their religion.
As being a brass instrument player, I can answer this easily. Some similarities are they are made of brass (of course). They all take air to play. You also have to buzz your lips into a mouthpiece that only brass instruments have. Some differences are they are different sizes. Different instruments take more or less air to play.
