(1) Electromagnetic relay: an electrical relay that works by using the suction effect of the current in the input circuit between the electromagnet core and the armature.
(2) Solid state relay: refers to a relay in which the input and output are isolated in which electronic components perform their functions without mechanical moving components.

(3) Temperature relay: a relay that acts when the outside temperature reaches a given value.
(4) Reed relay: A relay that uses the reed action sealed in the tube and has the dual functions of the electric shock reed and the armature magnetic circuit to open, close or switch the circuit.
(5) Time relay: when the input signal is added or removed, the output part needs to be delayed or limited to a specified time before closing or disconnecting its controlled circuit relay.
(6) High-frequency relay: a relay with minimum loss for switching high-frequency, radio frequency lines.
(7) Polarized relay: a relay that has the combined action of the polarized magnetic field and the magnetic field generated by the control current through the control coil. The direction of action of the relay depends on the direction of the current flowing in the control coil.