There are seven fundamental units in the SI system - Length (Metre), Mass (Kilogram), Time (Second), Electric Current (Ampere), Temperature (Kelvin),Luminous intensity (Candela) and Amount of substance (Mole).
There are two supplementary units in this system - Plane Angle (Radian) and Solid Angle (Steradian).
All the other units in the measurement system are derived from these fundamental units.