A camera, referred to as a camera, is a device that utilizes the principles of optical imaging to form an image and uses a negative to record the image. Many devices that can record images have the characteristics of a camera. Medical imaging equipment, astronomical observation equipment and so on. Camera is an optical instrument used for photography. The light reflected from the scene to be photographed through the camera lens (camera lens) and control the exposure of the shutter focus, the scene to be photographed in the dark box on the formation of a latent image of the light-sensitive material, after processing (i.e., development, fixation) constitute a permanent image, this technology is called photography. A digital camera is a camera that utilizes an electronic sensor to convert an optical image into electronic data. Unlike ordinary cameras that rely on the chemical change of silver bromide on film to record images, the sensor of a digital camera is a light-sensing charge-coupled -{zh-cn: device; zh-tw: component}- (CCD) or complementary metal-oxide-semiconductor (CMOS).