Mempool

A mempool serves as a temporary storage area where unconfirmed transactions reside after being verified by a node but before being included in a block. The mempool incorporates the Replace by Fee (RBF) mechanism, allowing transactions with higher fees to supersede those with lower fees. When the mempool becomes crowded with pending transactions, network congestion increases, leading to longer average confirmation times. Network nodes verify the validity of transactions in the mempool by checking correct signature schemes, ensuring outputs do not exceed inputs, and preventing double spending.