What Is a Mempool?
A mempool is a pool of unconfirmed transactions on the Bitcoin network. It is maintained by all nodes in the network and contains all valid but not yet confirmed transactions that have been broadcast to them. When miners create new blocks, they select which transactions from the mempool to include in their block based on certain criteria such as transaction fees and size.
The purpose of a mempool is to ensure that only valid transactions are included in newly mined blocks, while also allowing users to pay higher fees for faster confirmation times. The size of the mempool can vary depending on how many pending transactions there are at any given time, with larger pools indicating more demand for Bitcoin services than smaller ones. As miners prioritize high-fee paying transactions over those with lower fees, it’s important for users who want their transaction confirmed quickly to set an appropriate fee when sending funds.