In an RFID system, what component is electronically programmed to uniquely identify an item?

In an RFID (Radio-Frequency Identification) system, the component that is electronically programmed to uniquely identify an item is the transponder. A transponder consists of a microchip and one or more antennas. The microchip stores the unique identification data, which is programmed during manufacturing or later. This information is transmitted to a reader when the transponder is within range, allowing for automatic identification of the item it is attached to.

The transponder is essential for the functioning of an RFID system as it holds the key information that distinguishes one item from another. While the microchip is part of the transponder, it is the combination of the microchip and the antennas that defines the transponder's functionality in the context of RFID technology. The reader is responsible for emitting radio waves and receiving signals from transponders, and the antenna facilitates the communication between the reader and the transponder. Thus, while all components play a role in the RFID system, the transponder is specifically designated as the element that uniquely identifies the item.