>>3273206You use a fast shutter speed when you want to "freeze" fast-moving subjects, like sports, for example. You use slow shutter speeds when you want to create blur effects.
For example, if you shot a water fountain with a fast shutter speed then the drops of water would be individually visible, frozen in time. If you shot the same fountain with a a slower shutter speed you'd see blurry running water.
Aperture controls your depth of field. A wide aperture has a narrow depth of field. A narrow aperture has a large depth of field. So if you wanted to take a portrait of someone with the person in focus but the background blurry (bokeh) then you'd use a wide aperture. If you wanted everything in the frame to be in-focus then you'd use a narrow aperture.
That's a basic overview, anyway.
