Answer:
The United States and California are both among the largest countries in the world, and for this same reason, their geographies are very diverse, varying from region to region, and with very specific regional characteristics.
A common thing between these two countries is that both have coasts on the Atlantic, Pacific, and Artic Oceans. They also have their most important mountain ranges in the West, while the Eastern areas are mostly flat, with only the Appalachian Mountains in the U.S. being considered a proper mountain range.
The two countries also share the Great Lakes system, around which the most important Canadian city, Toronto, and the third largest American city, Chicago, are located.
In general terms, the main difference is that Canada is simply a much colder country. The northern parts of Canada are tundra where very few people live and where agriculture is not possible, while the Southern areas in the U.S. range from subtropical to tropical, with very large population, and an important agrarian economy.