What is Clique in Blockchain ?
Clique is a cross-client proof-of-authority (PoA) consensus protocol. It shadows the design of Ethereum mainnet, so it can be added to any client with minimal effort. In a PoA, the minted blocks are deemed to be signed by Trusted signers and thus, is a much simpler and energy efficient alternative to the Proof of Work consensus mechanism. Hyperledger Besu uses Clique consensus protocol.