D65 is a standard illuminant used in color science, representing average daylight with a correlated color temperature of approximately 6500 Kelvin. It serves as a reference point for color calibration in various industries, including photography, printing, and display technology. D65 is essential for ensuring consistent color reproduction across different devices and media. This illuminant is part of the CIE (International Commission on Illumination) standard illuminants, which help define how colors are perceived under specific lighting conditions. By using D65, professionals can achieve accurate color matching and maintain quality in their work, making it a crucial element in color management systems.