Relays are electrical switches that are operated by electrical impulses with the primary function to open and close a circuit, they can also be referred to as industrial switches.
A latching switch is a switch that maintains its state after being activated. A push-to-make, push-to-break switch would therefore be a latching switch – each time you actuate it, whichever state the switch is left in will persist until the switch is actuated again.
A latching relay will remain in the last position it when it was last powered. It is a relay that is set (ON) or reset (OFF) by the input of a pulse voltage. Even after the input voltage is interrupted, this relay maintains its set or reset condition until it receives the next inverting input. It is also called a keep relay.
A latching relay is a two-position electrically-actuated switch. It maintains either contact position indefinitely without power applied to the coil.