The San Francisco Chronicle and the Consumer Reports buying guide compare radiant and induction cooktops, listing pros and cons of each. General consensus is that the induction models are more precise, faster heating and superior in energy efficiency, but are also significantly more expensive.
Both models use electricity as their fuel. The conventional design uses the energy to heat a metal coil, which then transfers the heat to the pan. The induction cooktop uses copper coils to create an electromagnetic field that transfers the electrical energy directly to the pan, inducing the electrons in the cookware to heat in a more efficient process. For the process to work, however, special cookware must be used.