Glycerol is a 3-carbon compound with chemical formula C3H5(OH)3. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. Glycerol is a sugar alcohol.
Carbohydrate is a group of sugar that has compounds with different carbon numbers with general formula (CH2O)6. Carbohydrates are simple organic compounds that are aldehydes or ketones with many hydroxyl groups added, usually one on each carbon atom that is not part of the aldehyde or ketone functional group.