Candela

Candela is a unit of measurement for luminous intensity in the International System of Units (SI). It quantifies the amount of light emitted by a source in a specific direction. One candela is defined as the luminous intensity of a source that emits monochromatic radiation of frequency 540 × 10^12 Hz and has a radiant intensity of 1/683 watt per steradian. In practical terms, the candela helps in comparing the brightness of different light sources.