A cool white light bulb typically emits a bright, bluish-white light. It is called "cool" because it has a higher color temperature compared to warm white or soft white bulbs. Cool white light bulbs usually have a color temperature in the range of 4000K to 6500K. The higher the color temperature, the cooler and bluer the light appears. This type of light is often used in commercial and industrial settings, task lighting, and areas where a more vibrant and energetic illumination is desired.