Food has been cooked more or less the same way for centuries. Heat is produced by a device, which heats up a cooking vessel, which in turn heats and cooks the food. Induction differs completely from other cooking technologies in that, rather than producing heat that is then transferred to the cooking vessel, it makes the cooking vessel itself the original generator of the cooking heat. An induction cooker actually generates a magnetic field, which, if a ferrous material is used (a cast-iron skillet, for instance) transfers energy into the metal, causing it to become hot. Induction cooking thus requires a particular type of cookware, or the use of 'induction disks', which can be useful but which also nullify many of the advantages of induction.
Induction cookers offer many advantages. Among these are the facts that the field affects nothing outside the cooking vessel, and the heat generation stops when the vessel is removed from the surface; that the heat can be adjusted instantly and precisely; that it cooks faster than either regular electric or gas cooking; and that since heat is generated directly in the cooking vessel, there is no heat transfer loss.