Alcohol is a broad category of organic chemicals that contain one or more hydroxyl (-OH) groups attached to a carbon atom. The most common alcohol is ethanol, which is used as a fuel, solvent, disinfectant, and in alcoholic beverages. Other alcohols include methanol, isopropyl alcohol, and butanol, which are used in a variety of industrial applications such as fuel, solvent, and chemical intermediate for the production of other chemicals. Alcohols can be produced by fermentation, synthesis from olefins, or by reduction of aldehydes and ketones.