What is International System of Units (SI)?

The International System of Units (SI) is the international standardization for measurement, commonly known as the metric system. The SI is made up of seven base units including length (meter-m), time (second-s), amount of a substance (mole-mole), electric current (ampere-A), temperature (kelvin-K), luminous intensity (candela-cd), and mass (kilogram-kg). The system is used by nearly every country in the world and was officially signed into existence in Paris during 1875.