In Physics, we call those properties which can be measured and expressed with a number and a unit, magnitudes. Length, mass, volume, the quantity of a substance, voltage, etc, are magnitudes.
The following magnitudes are called fundamental physical magnitudes. If you add to these magnitudes two complementary ones: the solid angle and the plain angle, starting with them you can express ALL the other physical magnitudes.

Magnitudes
Symbol
Length
x
Mass
m
Time
t
Temperature
T
Intensity of electric current
I,i
Luminous intensity
I
Quantity of substance
mol