There are several legal ways to define an amount of firewood in Canada. We use a 'Cord' of wood. A ‘Cord’ of wood is measured by stacking wood 8 feet long, by 4 feet high, and 4 feet deep. This would measure 128 cu.ft. of wood. (8x4x4). This is also known as a bush cord. Here is a link to the Canadian website.
A face cord of wood is just the ‘face’ of the cord, so 8’x4’ of stacked wood. The difference you can have with a face cord is the width of the firewood. You can have 12” pieces to make a face cord of wood, as well as 16” or a 24” pieces.
We use face cords as a standard amount when we accept delivery orders, and all of our wood is cut to 12" pieces.