An automatic watch is a mechanical timepiece that that doesn't require the same winding frequency as a fully mechanical piece. An 'automatic' movement is a mechanical in the sense that it's not battery powered, as its power is derived from a coiled mainspring. However, where a true mechanical requires regularly winding or the watch will stop running, the automatic has a swinging metal rotor that rotates inside the case, and as it rotates it winds the mainspring "automatically". Hence the name 'automatic'. An automatic usually requires a couple of shakes in order to start running. The autos that are sold here are capable of being handwound, whereas earlier models do not allow for this. It is imperative that the autos sold by Primetiming ONLY be wound in the CLOCKWISE direction. Winding counter-clockwise can damage the winding pinion requiring repair or replacement.