Dear Ankas,
A snubber is simply a resistor in series with Capacitor and is used to minimize the sparking at mechanical relay contacts. As you minimize sparking relay contact life is improved and due to reduced sparking RFI is also reduced.

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R C

Don't try to build a snubebr on your own buy a readymade one. Since the capacitor used in snubbers have flame retarding properties.

In case of mechanical relays connect the snubbers across the load closest to the load i.e. in parrallel with the load closer to load.

When using Solid State Relays [SSR] connect the snubbers across the N/O of relay closest to relay i.e. parrallel with the load but closer to relay.

Regards,
Prahlad J. Purohit