Shutter Speed is something you have surely heard when talking about photos and pictures taken my a DSLR or digital camera. In some cases, the Shutter Speed is also referred to as exposure time. Both describe the same process when taking a photo.
The Shutter Speed is the amount of time when the sensor of a camera (and in old models the film) was exposed to light. In other words, it describes the time of how long the shutter of the camera is open. When taking a photo, Shutter Speed and aperture are both responsible for the lighting of the photo. There are many combinations possible that determine the look of the picture (pale, dark, motion blur, etc.). Short Shutter Speed, also called fast, (e.g. 1/500 s) is used to “freeze” fast moving objects. Long or slow Shutter Speed (e.g. 1/15 s) results in high motion blur.