What are the Axis and Allied powers of WWII and what are the differences?

World war 2 started when Hitler’s Germany attacked Poland, which had an alliance with France and England (Great Britain). That means that if Germany attacked Poland then France and England, which are in an alliance group, called the Allied powers. The allied powers where U.S., Britain, France, USSR, Australia, Belgium, Brazil, Canada, China, Denmark, Greece, Netherlands, New Zealand, Norway, Poland, South Africa, Yugoslavia, but the main countries in the war where the U.S., France, England, and the USSR. So when Germany attacked Poland, France and England attacked Germany on the west side of Germany but on the east side where the USSR was, the USSR didn’t attack Germany because they had a pact that is like a short alliance.