what is the difference between aperture and shutter in digital cameras?

Answer 1

Aperture controls the amount of light hitting the sensor (or film). Small aperture makes backgroud items look more in focus. Also called f-stop, or just F. Something with F8 will have more of the picture in focus than something with F3.

Shutter speed is how long the sensor is open. Usually in 1/x seconds. You want 1/1000 for fast, action photography. 1/30 is usually fine for posed pictures and still scenery. 1/30 is also about the limit for a hand held shot (hand shaking will make the pictures blurry).

Both of these also control the amount of light hitting the sensor. Longer shutter speeds and wider aperatures let more light in. Faster shutter and smaller aperature lets less light in. Photographers will play with these setting until they get the desired effect.

Answer 2

Aperture is the lens opening and the shutter is the thing that controls how long the light hits the film or sensor.

Answer 3

rule of thumb in photography:
aperture is size of opening in the shutter
shutter speed is the amount of time the shutter is open (how long the click lasts)
The great photographers of the film era were "f8 and be there"
Enjoy.