NFC Writer and Reader/RFID Reader and Writer devices are used for short-range wireless data transfer. NFC (Near Field Communication) and RFID (Radio Frequency Identification) devices can act as readers, writers, or both. RFID devices operate in three frequency ranges. They include a low frequency of 125-134 kHz, a high frequency of 13.56 MHz, and an ultra-high frequency of 856-960 MHz. RFID tags are used in a wide variety of markets. Applications include access control (such as electronic passes and security cards), tracking (such as library data) and livestock marking. Near-field readers/writers are used in smartphones and other mobile devices to provide payment services via a very short range (~10mm) contactless tap. NFC readers can read some RFID tags.

RFID readers and writers are capable of communicating with both active and passive RFID tags. Passive RFID tags do not have their own power source, but derive their power from the energy transmitted by the reader/writer. The reader/writer is capable of communicating with passive tags up to 25m away. Active RFID tags have their own power source and typically have a communication range of up to 100m. NFC is a subcategory of high frequency RFID. NFC differs from RFID in that NFC is designed to provide peer-to-peer secure communication between two devices. Another key difference is that RFID readers can scan multiple RFID tags simultaneously, while NFC readers can only communicate with one other device at a time. RFID readers and writers are not RFID tags, but any NFC device can be a reader and a tag.

Reader/writer modules are typically used in devices that read or update digital information on RFID tags and NFC devices. They are commonly used in printers to scan RFID or NFC and write that information to other labels and devices. Because RFID tags and NFC devices can be highly sensitive (for example, credit cards), security features for both NFC and RFID are included in application-specific standards. These devices, known as Secure Elements (SEs), have encrypted and secure tamper-resistant interfaces. It addresses the needs of applications such as authentication deployment, identification, pin management, and managed user credential visibility. The interaction between a trusted source (for example, a bank) or a trusted application (for example, a mobile payment app) and an NFC or RFID card is strictly controlled.