In manufacturing standard plywood, thin sheets or plies of different kinds of wood are trimmed and dried, then stacked one on top of the other at right angles. Then they are glued and hot-pressed together until they bond into a single unit. Often a higher-grade veneer is used on one or both sides of the finished sheet. In woodworking, routers come in 'fixed' and 'plunge' varieties. Fixed versions have a set depth.
Plunge styles have a movable table that the bit protrudes through at varying depths.
The term applies to any thin sheet of wood, but is often used to describe a finer grade of wood that is applied to the surface of a cheaper wood in order to improve its visual appeal. In the case of an electric motor, thin wire is wrapped around a magnetized armature, which spins to provide power for the tool it's housed in.