Biometric payments let shoppers authenticate a transaction by presenting a unique physical trait—such as a fingerprint, palm‑vein pattern, or facial image—to the terminal; the device captures the biometric, matches it locally against an encrypted template, and, if successful, tokenises the linked payment credential to complete the purchase just like a card‑present transaction. This approach eliminates PIN entry, speeds checkout, and enhances security because the biometric data never leaves the device and is extremely difficult to forge.