# Bluetooth Bluetooth is a short-range wireless standard (typically up to ~10 meters) for connecting devices directly to each other — earbuds, keyboards, speakers, smartwatches, car audio, fitness trackers. It is designed for low power and convenience rather than range or bandwidth. The low-energy variant, Bluetooth Low Energy (BLE), can run for months on a coin cell and underpins most wearables and beacons. ## Why it matters here Bluetooth is mostly neutral connectivity, with one privacy footnote worth flagging. BLE "beacons" broadcast a constant identifier, which retailers, venues, and ad networks use for proximity tracking — detecting which devices (and thus which people) enter a store, linger at a display, or attend an event. This was the mechanism behind several COVID-era exposure-notification systems and, more routinely, behind retail foot-traffic analytics. As an always-on radio that quietly announces a device's presence, Bluetooth is a minor tributary of the same ambient-tracking stream as [[Sensor]]s and the [[Internet of Things]], and a small [[Privacy]] consideration. Beyond that it carries little political cargo. ## See Also - [[Near-Field Communication]] — the even-shorter-range cousin behind tap-to-pay - [[Internet of Things]] — the device mesh Bluetooth helps connect - [[Privacy]] — beacon-based proximity tracking