What's the real difference between biomass and ethanol?
The best (partial) answer is Nuclear.
Current ethanol production uses only the edible part of the corn plant (throwing away most of the plant) and uses it for fermentation (inefficient) and then distillation is needed to concentrate the product (energy intensive) creating a product that is good to drink but not a good solution for our fuel problems.
Biomass is a generic term for the substrate. You can burn it directly to generate electricity. You can ferment it. You can gasify it and burn that to creat electricity with less air pollution. You can gassify it and then run it through a conversion plant and create methane, methanol, ethanol, or about anything you can make with petrochemicals.