Abbreviation: SWM = "Silent Wave Motor" (Nikon)
The abbreviations means "Silent Wave Motor"
Explanation from Nikon
Nikon´s AF-S technology is yet another reason professional photographers like NIKKOR telephoto lenses. AF-S NIKKOR lenses feature Nikon’s SWM which converts “traveling waves” into rotational energy to focus the optics. This enables high-speed autofocusing that’s extremely accurate and super quiet.
See examples of effected products
|Nikon AF-S 50mm f/1,4 G|
|Nikon AF-S 200mm f/2 G ED VR II|
|Nikon AF-S DX 16-85mm f/3,5-5,6 G ED VR|