Cards
Most payment systems were built around the needs of banks or merchants; card networks were engineered to make strangers trust each other in a fraction of a second. When people talk about retail checkout flows, authorization hold times, or dispute windows, they are almost always talking about cards.
ACH
The Automated Clearing House (ACH) is the foundational bank-to-bank electronic payment network in the United States. It processes tens of billions of transactions annually, powering corporate payroll, business-to-business supplier settlements, recurring subscription debits, and consumer utility payments.
Wires and instant payments
Most consumer payment methods rely on delayed reconciliation: cards grant an authorization hold and resolve settlement overnight, while ACH moves batches on business days and reports failures days later.
Wallets and other checkout methods
Modern e-commerce checkout flows rarely display a single form asking for card numbers. Instead, consumers encounter a cluster of branded payment buttons: Apple Pay, Google Pay, PayPal, Klarna, or "Pay by Bank".
SEPA
The Single Euro Payments Area (SEPA) is the integrated payment framework harmonizing electronic euro transactions across the European Union, the European Economic Area, the United Kingdom, Switzerland, and several adjacent European states. SEPA eliminates technical and legal borders for euro clearing: a cross-border transfer between Germany and Spain moves under the exact same regulatory rules and pricing structures as a domestic transfer inside France.