Noise
From The Glossary of Digital Photography
In digital photography, unwanted electronic noise in images. Noise is most often found in shadow areas when the exposure is increased during post-processing. It looks like multicolored confetti. In general, noise increases as the temperature of the sensor increases. Noise also increases as the camera's ISO setting is increased. Different cameras have different noise characteristics. Some software programs are specifically designed to help remove noise from images after they are created.
