Classification of organic compounds have open and closed chain compounds. Closed chain further have homocyclic and heterocyclic componds. In homocyclic compounds there are two types: alicyclic and aromatic compounds.
In alicyclic compounds, only singles bond are allowed, whereas in the aromatic category the ring of carbon atoms has alternate single and double bonds (i.e. conjugated double bonds). So what happens to the compounds which have a lone double or triple bond?
For example, cyclohexane is classified under alicyclic, but where would cyclohexene or cyclohexyne be classified?