The name 'Lux' is derived from the Latin word 'lux', meaning 'light'. It symbolizes brightness, clarity, and illumination. In the context of the International System of Units (SI), 'lux' is the unit of illuminance, representing luminous flux per unit area, specifically one lumen per square metre. This unit is used in photometry to measure the perceived intensity of light as it hits or passes through a surface, weighted according to the human eye's sensitivity to different wavelengths of light.