Sure... they can be made of anything you want...
The most popular (which is probably what you mean) are made of pancake mix (I think mostly wheat flour and some \"baking soda\" like agent mixed with egg and milk, not sure exactly) and those are served for breakfast with maple syrup.
They can also be made from buckwheat flour, whole wheat flour, etc. but they are pretty much similar.
And then - there are potato pancakes which normally are served with apple sauce and are not nearly as popular as the other kind.
(available mostly in German restaurants/neighborhoods)