Mempool
Also · Memory pool
The mempool is the set of valid, unconfirmed transactions a node holds while they wait for a block. Each node has its own, shaped by its relay policy.
The mempool is where a transaction waits between the moment it is broadcast and the moment a miner includes it in a block. Each node keeps its own. Two nodes rarely hold exactly the same set, because relay policies, timing and memory limits differ.
Miners generally pick the transactions that pay the most per unit of weight, so the mempool is also the market for block space. When it fills up, fees rise and low-fee transactions can wait for days or get dropped. Mempool explorers give a useful estimate of this market, not an absolute truth.
In French · Mempool