What Is a ‘Mempool’ and How Does It Relate to Transaction Fees?

The mempool (memory pool) is a waiting area for all unconfirmed transactions on a cryptocurrency network. When a user broadcasts a transaction, it first lands in the mempool.

Miners prioritize transactions with higher fees because they want to maximize their revenue per block. Therefore, a congested mempool (many waiting transactions) leads to a competitive bidding process, driving up the average transaction fee.