NFC Glossary
NFC terms and definitions explained. Learn about NDEF, NTAG, MIFARE, UID, and other NFC terminology.
NFC (Near Field Communication)
NFC is a short-range wireless communication technology that enables two electronic devices to exchange data when placed within approximately 4 centimeters of each other. NFC operates at 13.56 MHz and is widely used for contactless payments, access control, data sharing, and NFC tag reading/writing. Most modern Android smartphones include NFC hardware, making it possible to read and clone NFC tags with apps like NFC Clone.
NDEF (NFC Data Exchange Format)
NDEF is a standardized data format defined by the NFC Forum for storing and exchanging information on NFC tags and between NFC-enabled devices. NDEF messages contain one or more NDEF records, each holding a payload such as a URL, plain text, contact information (vCard), or custom application data. NDEF is the primary format that NFC Clone reads and writes when cloning NFC tags.
NTAG (NXP Tag)
NTAG is a family of NFC tag integrated circuits manufactured by NXP Semiconductors. The most common NTAG variants are NTAG213 (144 bytes), NTAG215 (504 bytes), and NTAG216 (888 bytes). NTAG chips are NFC Forum Type 2 compliant and are the most popular tags for consumer applications including smart home automation, marketing, gaming (Amiibo), and general-purpose NFC projects. All NTAG variants are fully supported by NFC Clone.
MIFARE
MIFARE is a series of contactless smart card and NFC chip products developed by NXP Semiconductors. The MIFARE family includes MIFARE Ultralight (64 bytes, used in transit tickets), MIFARE Ultralight C (192 bytes with 3DES encryption), MIFARE Classic (1K/4K with proprietary encryption), and MIFARE DESFire (high-security with AES encryption). NFC Clone supports MIFARE Ultralight fully and MIFARE Classic partially for unencrypted sectors.
UID (Unique Identifier)
UID is a unique hardware identifier burned into every NFC tag at the factory. The UID is typically 4 or 7 bytes long and is used by access control systems to identify specific tags. UIDs cannot be changed or cloned using standard Android NFC hardware because they are permanently written into the tag's read-only memory. This is a fundamental hardware limitation, not a software restriction.
RFID (Radio-Frequency Identification)
RFID is a broad category of wireless technology that uses radio waves to identify and track objects. NFC is a subset of RFID, specifically operating at the 13.56 MHz high-frequency band. While RFID encompasses technologies with ranges from centimeters to hundreds of meters, NFC is limited to approximately 4 cm, which provides inherent security benefits. RFID tags can be passive (powered by the reader) or active (battery-powered).
ISO 14443
ISO 14443 is an international standard for contactless smart cards operating at 13.56 MHz. It defines the physical characteristics, radio frequency interface, initialization, and transmission protocols for proximity cards. ISO 14443 has two variants: Type A (used by MIFARE and NTAG chips) and Type B. Most NFC tags and contactless payment cards comply with ISO 14443, making it the foundational standard for NFC technology.
NFC Forum
The NFC Forum is a non-profit industry association founded in 2004 by NXP Semiconductors, Sony, and Nokia. The NFC Forum develops and maintains the technical specifications and standards for NFC technology, including NDEF, NFC tag types (Type 1 through Type 5), and interoperability guidelines. The Forum ensures that NFC devices and tags from different manufacturers work together seamlessly.
Tag Emulation
Tag emulation is an NFC operating mode where an electronic device (such as a smartphone) behaves as if it were a passive NFC tag. In tag emulation mode, the device can be read by NFC readers just like a physical NFC card or sticker. This mode is the basis for mobile payment systems like Google Pay and Apple Pay, where your phone emulates a contactless payment card.
NDEF Record
An NDEF record is a single unit of data within an NDEF message. Each record contains a type, an identifier, and a payload. Common NDEF record types include URI records (URLs), Text records (plain text), Smart Poster records (rich links), and MIME type records (custom data). A single NFC tag can store one NDEF message containing multiple NDEF records, all of which NFC Clone can read and duplicate.
Reader/Writer Mode
Reader/Writer mode is an NFC operating mode where a device (typically a smartphone) reads data from or writes data to a passive NFC tag. This is the primary mode used by NFC Clone: the app reads NDEF data from a source tag in reader mode, then writes that data to a target tag in writer mode. Reader/Writer mode requires the tag to be within approximately 4 cm of the device's NFC antenna.
Peer-to-Peer Mode
Peer-to-Peer mode is an NFC operating mode where two active NFC-enabled devices exchange data bidirectionally. Unlike Reader/Writer mode where one device is passive, both devices in Peer-to-Peer mode actively generate radio fields. Android Beam (now deprecated) used this mode to share content between phones. Modern Android devices typically use alternative sharing methods like Nearby Share instead.
Card Emulation
Card emulation is an NFC operating mode where a device mimics a contactless smart card, allowing it to be recognized by NFC readers and point-of-sale terminals. Card emulation can be host-based (HCE, handled by the device's processor) or use a secure element (a dedicated hardware chip). Mobile payment services such as Google Pay and Apple Pay rely on card emulation to process contactless transactions.