CIE Standard Illuminant B is a reference light source defined by the International Commission on Illumination (CIE). It represents a type of incandescent light with a color temperature of approximately 2874 K, which is similar to the light produced by traditional tungsten bulbs. This illuminant is primarily used for colorimetry and color matching applications. The purpose of CIE Standard Illuminant B is to provide a consistent standard for evaluating colors under specific lighting conditions. It helps in ensuring that colors are perceived accurately in various industries, including photography, printing, and design, where precise color reproduction is essential.