A solenoid is a coil of insulated or enameled wire wound as a rod - shaped form. Devices of the kind can be used as electromagnets, as inductors and in electronic circuits.
Electromagnet differ from normal magnets in one major way. They are made by passing an electric current through a wire that has been wrapped around iron. The current creates a magnetic field and magnetises the iron core. When the current is turned off the iron loses its magnetism.