This seems like a simple question, but it is very confusing. Even those who have worked in this industry for many years may not be able to clearly describe the connection and difference between the two. To understand this, let's start with a simple diagram.
From the diagram above, it is very clear that there are significant differences between the two, but there are also overlaps.
　　Origin
The earliest prototype of RFID can be traced back to World War II. At that time, in order to effectively identify friend or foe aircraft, the Allied forces added a radio transmitter to their radar. When the radar detected an aircraft, it sent a specific radio wave. If it was a friendly aircraft, it would reply with a radio wave, and the radar would recognize it as friendly. If there was no response, it was considered an enemy aircraft. After decades of development, many frequency bands have emerged based on different applications. The field of use has also extended from the earliest single object identification to scenarios such as near-field payment.
Compared to RFID, NFC started much later, around 2003. The three IT giants PHLIPS, SONY, and NOKIA came together, unified certain aspects based on existing RFID, added some unique features, and introduced NFC technology.
　　RFID ClassificationThere are many ways to classify RFID, such as by active or passive, or by energy transfer method. To clarify the relationship between RFID and NFC, this article only discusses classification by frequency band.
Depending on the application field, RFID is divided into many frequency bands, from low to high:
1. Low Frequency: 125K, 134K
2. High Frequency: 13.56M
3. Ultra High Frequency: 900M
4. Microwave: 2.4G, 5.8G
Of course, these are not all the frequencies, just the ones we encounter most frequently in daily life. It is important to note that 900M and 13.56M are the most widely used. Common items such as bus recharge cards, meal cards, second-generation ID cards, and PBOC bank cards use these frequency bands, while product tags for inventory management mostly use 900M.
Unlike 13.56M, 900M is a general term and not a specific frequency. It varies by country. In China, the frequency band is around 900M, so 900M is commonly used as a general term.
　　Relationship between RFID and NFC
From the diagram above, it can be seen that the biggest commonality is that both use 13.56M. Since 13.56M is the RFID frequency band we encounter most, this is why many people confuse RFID and NFC. In fact, the scope of RFID is much broader than NFC. In addition to 13.56M, there are many other frequency bands, while NFC only uses the 13.56M frequency band. The original purpose of NFC was for near-field payment and small data exchange for loose authentication. NFC chose 13.56M as its foundation and added point-to-point communication. Traditional RFID only allows one reader to interact with one tag at a time, whereas NFC allows two readers to exchange data with each other.
At the same time, NFC does not support all 13.56M RFID protocols. It selectively supports only 14443 Type A and 15693 protocols, and does not support 14443 Type B, which is used for ID cards like ours.