At the General Conference on Weights and Measures, held in Versailles on November,26th in 2018, all Member States unanimously adopted the new definition of SI units. The new definition has been in force since 20 May, International Metrology Day. The exact definition now in force means that all SI units are based on 7 natural constants, making it unnecessary to derive units from other units. However, the associated changes only affect the high-precision measuring range and have no influence on everyday life. Anyone who now must learn the definition of a unit, can no longer refer to the original meter or kilogram but must remember the constants and how they apply to the respective units.