In photography, panning refers to the horizontal movement or rotation of a still camera. Panning a camera results in a motion similar to that of someone shaking their head "no". These images give you examples of panning.
The High-speed Train
© Evy JohansenPanning with Motion
© Peter K. BurianGetting Around...
© Horst RebingRed Dawn Wave
© David W. OriasZooming Through Fall
© Shawn JenningsSerious in Center Field
© Angie Sidles