Shutter speed
The shutter is part of the camera that opens and closes to let light in and take a picture. The shutter is how long the shutter stays open. The longer the shutter stays open the more light that is let in. But anything that moves the shutter is open longer will become a blur because to much light has been let in and too much movement has happened making the image unclear. However if a tripod is used the camera will capture a clear image as there is no movement. The shorter the shutter speed, you will get a clear picture of fast movement because less light has been let in. You will be able to capture fast movement such as fast running. Anything that moves while the shutter is open you will get a clear capture of the picture action.