NIKKOR lenses have a built-in Central Processing Unit (CPU). When a CPU lens is attached to a camera, the metal contacts shown below are used to communicate lens information and provide power and instructions to the lens from the camera. The number of CPU contacts varies between lenses.
NIKKOR Z-mount lens with CPU contacts on the left, NIKKOR F-mount lens with CPU contacts in the middle and a NIKKOR non-CPU lens on the right.
Non-CPU NIKKOR lenses refer to an early generation of NIKKOR lenses that were developed for Nikon film cameras. Photographers would manually control focus and aperture adjustment on the lens and camera to acquire optimal focus, exposure and composition. These lenses do not have CPU contacts to communicate data to the camera to perform focusing and other calculations.
For further details on NIKKOR F-mount lenses and their compatibility with cameras, please see the User manual or click here.