Payment Glossary: 70+ Payment Terms and Definitions for 2026

Understand the language behind payments, approvals, and smart retries.

Learn our 70+ terms

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A

API
A payment API connects checkout systems to gateways, processors, and banks so transactions, declines, and refunds move in real time. Strong API design supports smarter routing and better recovery from failed payments.
API
payments API, payment processing API, payments interface

P

Point of Sale (POS)
A point of sale is the hardware or checkout flow that captures payment details and starts authorization. Its setup affects decline handling, fraud controls, and transaction success.
Point of Sale (POS)
POS, payment terminal, checkout system