Definition: Shutter speed is the amount of time the digital camera's shutter remains open when capturing a photograph. The shutter is the piece of the digital camera that opens to allow light to reach the image sensor when the photographer presses the shutter button.
Shutter speed usually is measured in fractions of a second, such as 1/1000th of a second. Longer shutter speeds are required for low-light photos. With the shutter open for a longer amount of time, more light can strike the image sensor to record the photo. Shorter shutter speeds are required for photos containing fast-moving subjects, thereby avoiding blurry photos.
