What is commonly referred to as alcohol is just the most widely known example of a group of organic compounds which are collectively known as alcohols. The alcohol we drink is correctly called ethanol or ethyl alcohol and it has the chemical formula of C₂H₅OH. The alcohol functional group contains an -OH, or hydroxyl functional group, attached to carbon. Phenols are a subgroup of alcohol in which the hydroxyl groups are attached directly to the carbon atoms of a ring structure. Phenols have markedly different characteristics from the rest of the alcohols and the phenol group is discussed in a separate entry. Aliphatic dihydric alcohols are known as glycols.

If a compound possesses only one hydroxyl group then it is said to be a monohydric alcohol. Di-, tri-, and polyhydric alcohols also exist. Monohydric alcohols derive their names from the appropriate hydrocarbon with an ending of...