The amount paid to include a transaction in a block; incentivizes miners/validators and helps prevent spam.
Fees compensate block producers for processing and storing transactions. Levels depend on supply (block space) and demand (pending transactions).
BCH typically maintains sub-cent fees due to larger blocks, enabling microtransactions; other chains see spikes when blocks fill.
UTXO chains price fees by virtual size (vbytes); account chains use gas with per-op costs. Wallets estimate fees from mempool conditions to target confirmation times.
A wallet suggests a higher sat/vB during congestion to get confirmed in the next block; with empty mempools, minimum relay fees suffice.
All terms and definitions may update as the Cryptionary improves.