An adapter or adaptor is a device that converts attributes of one electrical device or system to those of an otherwise incompatible device or system. Some modify power or signal attributes, while others merely adapt the physical form of one connector to another.In short, an AC Adaptor converts the electric currents received by the electrical outlet into a typically lower alternating current that an electronic device can use. The second wire winding turns the newly created electric field into a smaller alternating electric current.