Getting started with RFID tags

RFIDs—we use them every day. With every visit to the supermarket, public library, bookstore, or department store, we handle objects that have an RFID tag, which stands for Radio Frequency Identification. For one, these small tags make it easier for shop owners to keep inventory by tracking the flow of items as they're brought in, moved around, and purchased. RFID tags are usually composed of a small electronic chip that can store a few thousand bytes and an antenna that commonly takes the shape of a tight spiral—sometimes squared, sometimes circular.