What is the negative used for without deleting it?

Delete or use it as a brochure after communicating with customers.

In photography, a base plate used to obtain images. The brightness of the obtained object image is opposite to that of the real object. At present, the widely used negative film is coated with silver halide on the base of acetic acid film. When light shines on silver halide, silver halide becomes black silver, which is fixed on the film base after development and becomes a common black-and-white negative. Color negative is coated with three layers of silver halide to show three primary colors. In addition to negative films, there are positive films and primary imaging films.