LPG is the generic name for commercial propane and commercial butane. There are hydrocarbon products produced by the oil and gas industries. Commercial Propane predominantly consists of hydrocarbons containing three carbon atoms, mainly propane (C₃H₈).

   Commercial Butane predominantly consists of hydrocarbons containing four carbon atoms, mainly n- and iso - butanes (C₄H₁₀).

   They have the special property of becoming liquid at atmospheric temperature if moderately compressed and reverting to gases when the pressure is sufficiently reduced. Advantage is take of this property to transport and store these products in the liquid state, in which they are roughly 250 times as dense as they are when gases.

   Butane is usually supplied to customers in cylinders, propane can be supplied in cylinders or in bulk for storage in tanks at the customers premises.