ACH is a form of EFT (electronic funds transfer) - essentially an online check where the user enters their bank routing number, account number, recipient, and amount. The gateways check a database to verify that the bank, at least, is real. PayPal supports ACH for members, but a lot of people aren't (and don't want to be).
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a 'spit' is a rod upon which savory food was roasted, turned in ancient times by a worker called a 'jack', a middle English word for an ordinary laborer (eg jack of all trades, steeplejack, lumberjack). Today, this job is usually referred to as a 'pitmaster'.
