I would like to know the difference between master/slave and replica set. I think it’s a similar technology, but why did MongoDB adopt a replica set? What are the advantages and disadvantages of each?

Hi @Kim_Hakseon , Master slave replication is the previous generation of current replica set replication. There is only one replication method. I suppose that you might mean the PV:0 and PV:1 change: https://docs.mongodb.com/manual/reference/replica-set-protocol-versions/ Best regards, Pavel