International System of Units
A system of physical units in which the fundamental quantities are length, time, mass, electric current, temperature, luminous intensity, and amount of substance, and the corresponding units are the meter, second, kilogram, ampere, kelvin, candela, and mole. The system has been given official status and recommended for universal use by the General Conference on Weights and Measures.
A system of units used in scientific work throughout the world and employed in general commercial transactions and engineering applications. Its units of length, time, and mass are the meter, second, and kilogram respectively, or decimal multiples and submultiples thereof. ( McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)