Silent Wave Motor
AF-S NIKKOR lenses feature Nikon’s Silent Wave Motor, which represents a significant advance in AF lens technology.
AS stands for Aspherical lens elements. This type of lens utilizes non-spherical surfaces on either one or both sides of the glass in order to eliminate certain types of lens aberration.
Select NIKKOR lenses have a focusing mode which allows switching from automatic to manual focusing with virtually no lag time by simply turning the focusing ring on the lens.
Rear Focusing System
A system in which only the rear lens group moves during focusing, thus eliminating changes in the physical length of the lens during focusing and enabling faster focusing. Such lenses are designated with RF on the lens barrel.