RFID, or Radio Frequency Identification, is a non-contact automatic identification technology that emerged in the 1990s. It enables information transmission and recognition via radio frequency signals without the need for mechanical or optical contact with the target. It can adapt to various harsh working environments and simultaneously identify multiple high-speed moving objects with efficient and convenient operation.

1. Core Composition and Classification
System Composition: It consists of three parts: electronic tags, readers, and antennas. The tags store unique identity identifiers and business data, while the readers are responsible for transmitting radio frequency signals, reading and decoding the information returned by the tags, and ultimately uploading the data to the backend system for processing.
Common classifications:
Passive tag: No built-in power source, relies on electromagnetic waves emitted by the reader to obtain energy, low cost, compact size, and is currently the mainstream product in the market;
Semi-active tags: equipped with built-in micro batteries to power the chips, offering faster response times and higher recognition efficiency than passive tags;
Active tag: equipped with an independent power supply module, it offers a longer read range, greater storage capacity, and can actively transmit signals outward.
Common frequency bands: Covering three types—low frequency (125KHz-135KHz), high frequency (13.56MHz), and ultra-high frequency (860MHz-960MHz), with different bands suitable for varying identification ranges and application scenarios.
II. Developmental Process
The prototype of RFID technology can be traced back to the enemy identification systems during World War II. In 1948, the principle of backscatter communication was systematically elucidated, laying the theoretical foundation. After the introduction of the ISO/IEC 18000 series standards in the 1990s, the technology entered a phase of standardization and commercialization. Post-2010, with a significant decline in tag costs, it gradually became widely adopted across various industries, now standing as one of the core supporting technologies for the perception layer of the Internet of Things.

III. Typical Application Scenarios
In addition to enabling seamless access, attendance tracking, and payment functions within campus card systems, RFID is widely utilized in various fields such as logistics and warehouse traceability, industrial asset management, access control and security, animal identification, vehicle anti-theft, and intelligent library management, significantly enhancing automation efficiency across industries.