Final answer:
The metric system, also known as the International System of Units or SI, is used globally and is founded on multiples of 10 for easy conversion. It includes universal units like the meter, liter, and gram, and was officially adopted worldwide in 1960.
Step-by-step explanation:
The metric system, also called the International System of Units (SI), is used in virtually all countries around the world. It is the standard system of measurement for science, agreed upon by scientists and mathematicians, and is based on the multiples of 10 which makes it very simple to convert between its units.
The SI units include both fundamental and derived units, with the most commonly known being the meter, liter, and gram. The system was established in France in 1795 and formally adopted internationally in 1960. The United States is an exception, where the customary or imperial system is still extensively used.