Based on the nature of bonding, organic compounds are classified into two types: aromatic and aliphatic. The main differences between the types is listed below.

• Aliphatic compounds can be saturated (alkanes) or unsaturated (alkenes and alkynes). They have straight, branched or cyclic structures whereas aromatic compounds contain a cyclic structure.
• Reactions of aromatic compounds are contradictory to the unsaturated aliphatic compounds.
• Unsaturated aliphatic compounds can decolorize the coloured solutions of bromine and Potassium permanganate by oxidation, but aromatic compounds does not. Aliphatic compounds can be identified by non–sooty flame, while the aromatics give sooty flame.
• Aromatic compounds differ in physical and chemical properties from that of alipahtic compounds due to π electrons. The electrons are delocalized over the entire benzene or the cyclic ring.

The following table represents examples of aliphatic and aromatic compounds that have commercial importance.