An NFC reader is the device that detects and communicates with a nearby NFC card or tag. It generates a short-range radio field, receives the tag’s response, and passes the resulting data to software that decides what action to take.
Readers are the interface between a physical tap and a digital operation. In a simple project, a card may select a sound; in other systems, a tap can trigger access control, payment, or automation. Security depends on what the reader accepts and how the software handles the input. A reader detecting a tag does not, by itself, prove that the tag or its user is authorized. Systems should validate inputs and use appropriate authentication when actions have security consequences.