The amount of substance is measure of the number of entities like atoms, molecules, ions, electrons or protons, etc., present in a substance.
Generally, the amount of substance is directly proportional to the number of atoms or molecules.
The ratio of the mass of a sample by its amount of substance is the molar mass, whose SI unit is kilograms (or, more usually, grams) per mole, which is about \(18.015\) \(g/mol\) for water,  \(55.845\) \(g/mol\) for iron.
Mole is a SI unit of  the amount of a substance, and it is denoted as 'mol'.

Mole is defined as the amount of substance that contains a value of \(6.023 × 10^{23}\), and its number is known as Avogadro number.
Luminous Intensity measures the power of the emitted light, by a light source in a particular direction, per unit solid angle.
Candela is an SI unit of luminous intensity, and it is denoted as 'cd'.
One candela is approximately equal to the light emitted from a wax candle. A common candle emits light with roughly \(1\) \(cd\) luminous intensity.
Photometer is a device used to measure luminous intensity.
Photometer is used in photography, soil testing, and the water industry.