There are all kinds of alcohol molecules, but the one that people most often pour down their throat is ethanol. This is a molecule that, in technical chemistry terms, looks like a doggie. Two carbon atoms are stuck together to support an oxygen head. Six hydrogen atoms spread out over the molecule to give each of the carbon atoms two feet, the oxygen atom a nose, and the rear carbon atom a tail. Ethanol is compact and water soluble, so like a doggie, it gets into all sorts of places that it's not supposed to.