Properties which depend upon the amount of the substance present in the system are called extensive properties. Mass, Volume, Number of moles, Enthalpy, Entropy, Free energy, Heat Capacity, Force, Surface Area etc are the example of extensive properties. These properties are additive. If mass of the gas is changed, the volume is also changed and so is the number of moles and their internal energy of the system.
Properties which don't depend upon the amount of the substance present in the system are called intensive properties. Temperature, Pressure, Boiling Point, Melting Point, Specific Heat, pH, Vapour Pressure, Surface Tension, Viscosity etc are the example of intensive properties. If temperature of a glass of water is 25oC, then each and every drop of water in this glass has the temperatue of 25oC. These properties are non additive.