Classification of supply determines whether a transfer is taxed as goods or services, affecting GST treatment and rates. Classification under Schedule II read with Section 7(1A) treats transfer of title in goods as Supply of Goods, while transfer of rights in goods and transfer of undivided shares are Supply of Services. The parties' intention governs passage of title. Service categorisation may adopt tax rates of the underlying goods where notified. Guidance covers composite-supply principal-supply analysis, specific rate and reverse-charge adjustments for leasing and tradable certificates (PSLCs, RECs), IGST treatment for inter state certificate trading, and treatment of printed books sold by rights holding suppliers as goods.