Units are measurement standards. System of units is classified into two categories: Fundamental units and Derived units.
Fundamental units are further subdivided into following types:
- MKS - meter, kilogram, second
- CGS - centimeter, grams, second
- FPS - foot, pound, second
- S.I - precise form of MKS, used internationally.
Derived units are units derived from fundamental. It is a set of fundamental units which are used to express some form. Derived units are either dimensionless or a product of fundamental units.
Example: Kg/m², ft/in², psi, etc.
Fundamental Units
SI or MKS
- Length - millimeter; mm
- Mass - kilogram, kg
- Time - seconds; s
- Temperature - Kelvin, K
- Electric Current - Ampere; A
FPS system of units
- Length - foot; ft
- Mass - pound; lb
- Time - seconds; s
- Temperature - Fahrenheit; F
- Electric Current - Ampere; A
CGS
- Length - centimeter; cm
- Mass - gram, g
- Time - seconds; s
- Temperature - Celsius, C
- Electric Current - Ampere; A
