Illuminants are sources of light that provide illumination in various settings. They can be natural, like the Sun, or artificial, such as light bulbs and LEDs. The quality and color of light emitted by an illuminant can affect how we perceive colors and details in our environment. Different illuminants have distinct color temperatures, measured in Kelvin. For example, a warm light (around 2700K) resembles the glow of a candle, while a cool light (around 5000K) mimics daylight. Understanding illuminants is essential in fields like photography, design, and architecture, where lighting plays a crucial role in aesthetics and functionality.