Contactor is an electrical switching device. It is used for switching an electrical circuit on and off. It is a special type of relay, but there is a basic difference between the contactor and a relay. The contactor is mostly used in applications where higher current carrying capacity is involved, while the relays are used for lower current applications. Contactors are compact and can be field-mounted easily. Usually, these devices feature multiple contacts. The contacts are mostly normally open, and they provide operating power to the load whenever the contactor coil is powered. Contactors are popularly used with electric motors.