RFID (Radio Frequency IDentification)

A radio technology that operates at low power and short distances.

In logistics, RFID "tags" are small, passive electronic radio versions of barcodes, designed to identify products and be scanned by RFID readers tracking inventory.

In phones, a closely-related technology called NFC can be used for payments and authentication. This is more accurately called a "contactless" technology, as opposed to RFID.