Definition:Fundamental Unit (Physics)

Definition
A fundamental unit a unit of measurement for a measurable physical property from which every other unit for that quantity can be derived.

The fundamental unit for a particular measurable quantity is chosen by convention.

They are the units of the fundamental dimensions of physics.

Examples
There are various conventions, as follows:
 * SI units (Système International), which evolved from the MKS system
 * MKS, that is, Meter-Kilogram-Second
 * CGS, that is, Centimeter-Gram-Second
 * Imperial or FPS: that is, Foot-Pound-Second.

There are other more specialized ones.

Also see

 * Definition:Derived Unit