The metric system is a system of measurement that succeeded the
decimalised system based on the meter, which had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the
International System of Units (SI) in the mid-20th century, under the oversight of an international standards body. Adopting the metric system is known as
metrication.
Metric units are units based on the meter, gram or second and decimal (power of ten) multiples or sub-multiples of these. The most widely used examples are the units of the International System of Units (SI). By extension they include units of electromagnetism from the CGS and SI units systems, and other units for which use of SI prefixes has become the norm. Other unit systems using metric units include:
Source: Wikipedia
No units has been chosen.
