The mempool (memory pool) is a smaller database of unconfirmed or pending transactions which every node keeps.
The mempool (memory pool) is a smaller database of unconfirmed or pending transactions which every node keeps. When a transaction is confirmed by being included in a block, it is removed from the mempool. Nodes share mempool data by relaying signed transactions to each other, but there is no single mempool and few if any nodes keep the entire mempool. Miners draw transactions from the mempool to include in their blocks.
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