The calotype, also known as the talbotype, is an early photographic process invented by William Henry Fox Talbot in the 1840s. It involves exposing paper coated with a light-sensitive chemical to light, which creates a negative image. This negative can then be used to produce multiple positive prints on paper. The calotype was significant because it introduced the concept of using negatives to make multiple copies of a photograph, which led to the development of modern photographic techniques.