Watt is typically used to measure the power consumption of a light fixture, representing the amount of electrical energy consumed per unit of time. Meanwhile, lumen is used to measure the brightness or luminous flux of a light source, indicating the total amount of light emitted. Generally, a higher wattage does not necessarily mean a higher brightness, as brightness depends on the number of lumens.

Simply put, watt represents the electrical energy consumed by a light fixture and is commonly used to measure its power. In the past, when purchasing light fixtures, brightness was often measured based on the wattage of the light bulb. For example, a 100-watt incandescent bulb was needed to illuminate a living room. Consequently, wattage became the standard for measuring the brightness of light fixtures. However, the working principle of incandescent bulbs resulted in low energy efficiency, with most of the electrical energy being converted into heat rather than light.

With technological advancements, LED (Light Emitting Diode) lighting, which is more efficient and energy-saving, has gradually replaced traditional light bulbs. Unlike traditional fixtures, LED lighting devices often use less electrical energy to produce the same brightness of light output because they operate differently, converting most of the electrical energy into light rather than heat. Therefore, "lumen" has become the new standard for measuring the brightness of light fixtures, gradually replacing the conventional practice of using wattage as the benchmark.

Different types of lamps produce different lumens at the same wattage