Key light is the primary source of illumination in photography and film. It is typically positioned in front of the subject to highlight their features and create depth. The intensity and angle of the key light can significantly affect the mood and tone of the scene, making it a crucial element in visual storytelling. In a standard three-point lighting setup, the key light is complemented by a fill light and a backlight. The fill light softens shadows created by the key light, while the backlight adds dimension by separating the subject from the background. Together, these lights enhance the overall composition.