1. basic

The Mempool, short for memory pool, is a temporary storage space in a node for all pending transactions that have not yet been included in a confirmed block. Not all nodes have a mempool, and those that do may not accept all broadcast transactions.


"When a Bitcoin transaction is made, it first goes into the mempool before being included in a block."

2. mining

Miners running full nodes collect all broadcast transactions into their mempool. They typically select the transactions with the highest fees for inclusion in the next block, confirming them and removing them from the mempool.


"Miners prioritize transactions with higher fees from the mempool when creating a new block, as these transactions provide a greater reward."

3. network

As a block is validated by the rest of the network, each node removes the block's included transactions from their own mempool. This process ensures that transactions are not included in more than one block.


"Once a block is confirmed, the transactions it contains are removed from the mempool of each node, preventing them from being included in future blocks."

4. congestion

The size of the mempool can indicate the level of congestion on the network. If there are more transactions than can be included in a single block, the mempool grows, leading to longer confirmation times and higher fees.


"During periods of high transaction volume, the mempool can become congested, leading to longer wait times for transactions to be confirmed."

* All terms and definitions may update as the Cryptionary improves.