CompTIA Tech+ (FC0-U71)InfrastructureHard
A retail customer taps their smartphone against a payment terminal to complete a purchase without opening any app or entering a PIN. Which wireless technology enables this short-range contactless communication?
- AInfrared (IR)
- BWi-Fi Direct
- CBluetooth
- DNFC
Show answer & explanationAnswer & explanation
Correct answer: D. NFC
NFC (Near Field Communication) enables secure, short-range wireless communication (typically within a few centimeters) used for contactless payments and tap-to-pair actions. Bluetooth and Wi-Fi Direct have longer ranges and require pairing, while IR requires line-of-sight and is not used for payments.
Why the other options are wrong
- A. Infrared requires line-of-sight and is largely obsolete for this use.
- B. Wi-Fi Direct is used for device-to-device networking, not payments.
- C. Bluetooth has a longer range and typically requires a pairing process.
NFC (Near Field Communication)
A short-range wireless technology (a few centimeters) used for contactless payments, tap-to-pair, and data exchange.
- Range: typically under 4 cm
- Used in mobile payment systems (Apple Pay, Google Pay)
- No manual pairing required
- Derived from RFID technology
Memory trick: NFC = 'Near Fingers Contact'—just tap and go.