Amount of substance is a measure of the number of entities like atoms, molecule, ion, electron or proton, 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, and \(55.845\) 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 is the measure of 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 the luminous intensity.
Photometer is used in photography, soil testing, and the water industry.