RFID (Radio Frequency Identification) system in libraries is a technology-based system that uses RFID tags and readers to manage and track library materials, such as books, DVDs, and CDs. RFID technology enables library staff to quickly and accurately check in, check out, and locate library materials, and also provides security against theft.

In a typical RFID library system, each library item is affixed with an RFID tag that contains a unique identification number. When a library patron checks out an item, the item's RFID tag is read by an RFID reader, and the item is automatically registered as checked out in the library's system. When the patron returns the item, the RFID tag is read again, and the item is registered as checked in.
RFID technology also allows libraries to perform inventory management and shelf management tasks more efficiently. Library staff can use handheld RFID readers to quickly locate misplaced items or items that are out of order on the shelves.
RFID library systems also provide a security feature that alerts library staff if a tagged item is being taken out of the library without being properly checked out. If an RFID reader detects an unregistered item passing through the library's security gates, an alarm is triggered, and library staff can investigate.
Overall, RFID systems in libraries offer a more efficient and effective way to manage and track library materials, improving the library's overall operation and patron satisfaction.