Camera

Is a device that records images, either as a still photograph or as moving images known as videos or movies. The term comes form the camera obscure (Latin for dark chamber.), an early mechansium of projecting images where an entire room functioned as real time imaging system; the modern camera evolved from the camera obscura.
Shutter

In photography, a shutter is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light - sensitive electronic sensor to light to capture a permanent image of a scene.

Shutter speed

B = Bulb
1 second
1/2
1/4
1/8
1/15
1/30
1/60
1/125
1/250
1/500
1/1000

Aperture

In optics, an aperture is a hole or a opening through which light travels. In phototography this can be measured in increments called f stops.

Lens

The of a camera captures the light from the subject and brings it to focus on the film or detector.

Exposure control

The size of the apeture and the brightness of the scene controls the amount of light that enters the camera during a period of time, and the shutter controls the length of time that the light hit's the recording surface. Equivalent exposures can be made with a larger aperture and a faster shutter speed or a coresponding smaller aperture and with the shutter speed slowed down.