These 2 photos demonstrate the effect of shutter speed and the appearance of water movement. The 1st image shows blurred movement due to the slower shutter speed while the 2nd image stops the movement at 1/320th of a second. Click on the images to see larger versions which will show the effects and differences a little better.
Look in your camera manual for a setting called shutter priority (TV). You set the shutter speed and your camera will choose the correct aperture for exposure. If your images appear dark in the display you will need to increase your ISO speed.
When taking action photos you will want to pay attention to your shutter speed if you want to freeze the action. Ready, set, GO!!!