ACH
Also called: Automated Clearing House, ACH transfer, BACS
ACH is the batch network behind US direct deposits, direct debits and most bill payments — cheap, reversible, and historically slow, settling in one to three days. Batch processing is why an ACH transfer costs cents while a wire costs tens of dollars. Reversibility makes it safer for consumers and is exactly why sellers of high-value goods insist on wires instead.