Negative
A negative is a sheet of transparent film coated with silver salts that react when exposed to light, typically within a camera. In black and white negatives, a single layer of silver salts reacts to white light (the full spectrum of light), resulting in an image where shadows appear light and highlights appear dark, effectively reversing normal vision.
In color negatives, there are usually three layers of silver salts, each reacting to one of the primary colors of light: red, green, or blue. This layering allows the negative to capture the full color spectrum, which can then be processed to produce a positive color image.