Organic compounds that contain the –OH group. In systematic chemical nomenclature alcohol names end in the suffix -ol. Examples are methanol, CH₃OH, and ethanol, C₂H₅OH. Primary alcohols have two hydrogen atoms on the carbon joined to the –OH group (i.e. they contain the group –CH₂–OH); secondary alcohols have one hydrogen on this carbon (the other two bonds being to carbon atoms, as in (CH₃)₂CHOH); tertiary alcohols have no hydrogen on this carbon (as in (CH₃)₃COH): see formulae. The different types of alcohols may differ in the way they react chemically. For example, with potassium dichromate(VI) in sulphuric acid the following reactions occur:

primary alcohol → aldehyde → carboxylic acid

secondary alcohol → ketone

tertiary alcohol – no reaction

Other characteristics of alcohols are reaction with acids to give esters and dehydration to give alkenes or ethers. Alcohols that have two –OH groups in their molecules are diols (or dihydric alcohols), those with three are triols (or trihydric alcohols), etc.

Alcohols

https://www.acdlabs.com/iupac/nomenclature/79/r79_202.htm Information about IUPAC nomenclature