A pending block refers to a block that has been created but has not yet been added to the main blockchain. When miners find a new block, it must be validated and accepted by the network. This process involves ensuring that all transactions within the block are legitimate and that the block itself follows the rules of the protocol.During this waiting period, the block is considered “pending.” Other miners might discover new blocks during this time, leading to multiple blocks being created almost simultaneously. The network will eventually choose one of these blocks to add to the blockchain, typically the one that is accepted first by a majority of miners, based on the longest chain rule.Pending blocks play a crucial role in ensuring the integrity and security of the blockchain. Once a block is confirmed and added to the chain, the transactions it contains are considered irreversible, providing a permanent record on the blockchain. Until then, transactions remain contingent on the consensus of the network.