It is the chemistry of specific carbon compounds except oxides, carbonates, and carbides.
Organic compounds are composed of carbon and hydrogen only. Examples: Methane (CH4), and ethane (C2H6).
Compounds with the same molecular formula but different structural formulas are known as isomers, and the phenomenon is known as isomerism. Examples: Butane and isobutane are two different compounds with the same molecular formula C4H10.