Glass or ceramic smooth cooktops can have induction elements, but the majority of them are conventional electric coil. Induction element cooktops are significantly more expensive than conventional element smooth-top ovens, and they require special cookware.
Conventional models heat a metal coil under the glass, transferring the heat from the element to the surface and then to the pan. Induction-style elements have copper coils that do not generate heat. Instead they create an electromagnetic field that reacts with a magnetic material, such as iron in the pan, turning the pan into a burner. This process wastes less energy, making the induction method significantly more efficient.