A camera is an optical instrument that captures images. Most cameras can capture 2D images while some more advanced models can capture 3D images. At a basic level, most cameras consist of a sealed box (the camera body), with a small hole (the aperture) that allows light to pass through and capture an image on a light-sensitive surface (usually a digital sensor or photographic film). Cameras have various mechanisms to control how light falls onto the light-sensitive surface, including lenses that focus the light and a shutter that determines the amount of time the photosensitive surface is exposed to the light
Most cameras capture light from the visible spectrum, while specialized cameras capture other portions of the electromagnetic spectrum, such as infrared.
All cameras use the same basic design: light enters an enclosed box through a converging or convex lens and an image is recorded on a light-sensitive medium. A shutter mechanism controls the length of time that light enters the camera.
Most cameras also have a viewfinder, which shows the scene to be recorded, along with means to adjust various combinations of focus, aperture and shutter speed
