What is the difference between Butane and propane?

propane has to be stored at higher pressure than butane butane can be used in aerosols as a propellant, propane cant butane is about 10-15% more efficent than propane as a fuel

butane has four carbon atoms: CH3-CH2-CH2-CH3

propane has three: CH3-CH2-CH3

so propane has a lower boiling point, higher vapor pressure.