Panning.

Panning can be used when you want to take an image which is moving very quickly but you want the image to be still. What you do is set your camera to Shutter Priority and use a slow shutter speed, focus on the subject i.e. a man on a bike, move the camera following the moving object around the same speed. Once your image has been exposed you will see the man on the bike would be still and the background would be a blur.