Twenty-two coherent derived units have been provided with special names and symbols. These are called coherent derived units, which can always be represented as products of powers of the base units. The system can accommodate coherent units for an unlimited number of additional quantities. The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, electric current), kelvin (K, thermodynamic temperature), mole (mol, amount of substance), and candela (cd, luminous intensity). : 123 Established and maintained by the General Conference on Weights and Measures (CGPM ), it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce. The International System of Units, internationally known by the abbreviation SI (for Système International), : 125 : iii is the modern form : 117 of the metric system and the world's most widely used system of measurement.
