International System of Units (SI)
Definition - What does International System of Units (SI) mean?
Techopedia explains International System of Units (SI)
It is declared as an evolving system, so there can be new units and prefixes created, and even unit definitions can be modified through an international agreement as the technology and precision of measurements improve.
All SI units can be expressed directly or in terms of standard multiples or fractional quantities by powers of 10 ranging from 10-24 to 1024.
The seven base SI units are as follows: