What is GRANDPA Consensus Mechanism (Polkadot)?

GRANDPA (GHOST-based Recursive Ancestor Deriving Prefix Agreement) is one of the two central components of the hybrid consensus mechanism that Polkadot utilizes to secure and maintain its network. GRANDPA is a mechanism for finalizing the state of the blockchain, while its counterpart, Blind Assignment for Blockchain Extension (BABE), is a mechanism for producing blocks.