1.Fundamental units :Every quantity is measured in terms of some arbitrary ,but internationally accepted units ,called fundamental units .
2.Derived units : Units which are derived from fundamental units ,are known as derived units
e.g., the unit of area ,velocity,acceleration,pressure etc.
3. system of units: there are four system of units ,which are commonly used and universally recognized .
These are known as :
1.C.G.S units
2.F.P.S units
3.M.K.S units
4.S.I units ( International System of units)
