The SI system is based on the metric system .Metric system is a system of measurement. We consider the measurement of mass, length, time, temperature, electric current , amount of substance and luminous intensity. Its not always convenient to employ fundamental SI units for trace substances, we therefore use prefixes to change the size of the unit. Volume is a very important physical quantity in chemistry which is not a fundamental SI unit but a derived quantity from length.
1liter = 1000 cubic centimeters = 1000 mL