As you probably know, Bluetooth low energy (BT LE) is a wireless personal area network technology which uses a minimum of power to broadcast messages to receivers nearby.
Bluetooth LE is a common standard but it is most popular under the name of IBeacons. IBeacons is a protocol coming from Apple, so it is just a class of Bluetooth low energy (LE) devices that broadcast their identifier to nearby portable electronic devices.
IBeacons can basically exchange two parts of data: that unique identifier and the signal strength. This makes it possible to figure out the (fixed) position of the IBeacon. And if you receive the signals of multiple beacons you can triangulate your own position between them.
In 2015 Google launched a competing, but similar, beacon standard called Eddystone. It has a richer functionality because it can exchange more information.
Far less known is that Windows 10 also supports the beacon technology, it’s not just Apple and Android which are having fun with it. In Windows, there is this Windows.Devices.Bluetooth.Advertisement library:
“It allows apps to send and receive Bluetooth Low Energy (LE) advertisements.”