Here in the United States, Canadian bacon is very similar to ham. It can either be a whole cut from the pork loin or it can be compressed from various different cuts. Check the labeling! If the only ingredient is "pork," then it's probably from the loin. If you see a lot of additives, then it's more like to be the processed version.
Canadian bacon comes in thinly-cut uniform rounds about the size of a silver dollar, and it's usually pre-cooked and smoked. It's a leaner meat and so doesn't crisp up like the strip bacon coming from the pork belly. We think it has a sweet meaty flavor and a nice juicy texture - very much like cured ham.
In Canada and other parts of the world, Canadian bacon is usually called back bacon or peameal bacon. It is made exclusively from lean boneless pork loin that is cured in a sweet pickle solution but not typically smoked. Traditionally, the cured loin gets rolled in peameal (ground dried peas) or cornmeal before being sliced.
We've never had real Canadian bacon, so we can't compare the two ourselves. Canadian readers, how would you describe the difference?
Related: Ingredient Spotlight: Ham Steak