Methanol is the product of replacing the hydrogen atom of methane with hydroxyl (an atomic group composed of hydrogen and oxygen, not hydroxyl). Ethanol is the product of replacing the hydrogen atom of ethane with hydroxyl group, which is usually called ethanol. The molecules are different. Methane: h | h-c-h | h methanol: h | h-c-oh | h ethanol: h ||| h | h-c-c-oh || h They have different molecular formulas and different chemical and physical properties. If two hydrogen atoms in methane are replaced by hydroxyl groups, it is called methyl glycol, and there are also methyl triol and ethylene glycol. High school organic chemistry has a deep discussion on this.