Consensus is the base of the crypto world to verify each and every transaction transparent to the whole network to assure secured operation.
Confirmation is a critical concept in cryptocurrencies. You could say that cryptocurrencies are all about confirmation. As long as a transaction is unconfirmed, it is pending and can be forged. When a transaction is confirmed, it is set in stone. It is no longer forgeable, it can‘t be reversed, it is part of an immutable record of historical transactions: of the so-called blockchain.