Glossary
Processor
The technical provider that transmits transaction data between the gateway, the card schemes and the issuing and acquiring banks.
The processor handles the message exchange that makes an authorization possible, and often performs clearing and settlement file generation as well. Some institutions act as both processor and acquirer; others separate the roles.
From an enterprise integration perspective, the processor's API characteristics — timeouts, error taxonomy, settlement file format, sandbox quality — have a large effect on how much work an integration actually is.