The difference between methyl alcohol and ethyl alcohol is that methyl alcohol is wood alcohol, which is poisonous if it's ingested. Ethyl alcohol is grain alcohol. Although it also is dangerous in large amounts, it is the alcohol in alcoholic beverages.
Alcohol begins with a simple water molecule. Replacing one of the hydrogen atoms with a chain of one carbon atom and three hydrogen atoms produces methyl alcohol. The formula is CH4O. To get ethyl alcohol, one of the hydrogen atoms on the carbon chain that produced methyl alcohol is replaced by another carbon chain. The formula for this alcohol is C2H6O.
Besides being part of alcoholic beverages, ethyl alcohol, also called ethanol, has also found use as a fuel to supplement or replace gasoline in car engines. As with alcoholic drinks, ethanol can be distilled from corn or sugar cane, though it's adulterated with gasoline to make it unpalatable. However, ethanol contains considerably less energy than gasoline. Moreover, since so much farmland needs to be dedicated to its production, its eco-friendliness is questionable.
Methyl alcohol, also called methanol, is used as a solvent and an antifreeze as well as a fuel. If even a small amount is ingested, it degrades into formic acid, which then attacks the optic nerve. This results in blindness. Only 3.4 fluid ounces of methanol is enough to be fatal.