The history of beacons starts a long time ago as a way to signal over long distances using fire or later light houses. Beacons, as pertains to the Internet of Things (IoT), started with Bluetooth and accelerated with advancement to Bluetooth Low Energy (BLE), now referred to as Bluetooth Smart.
The Bluetooth protocol (invented by telecom vendor Ericsson in 1994)  has been around for many years enabling wireless transfer of data including both audio and video by the creation of a sharable wireless personal network.
In 2010 BLE, as part of Bluetooth 4.0, was released with a focus on the transfer of simple links URLs, and similar small amounts of data, instead of video and audio directly. It is called Low Energy as the protocol was adapted to be less battery intensive, which opened up a lot of possibilities.
Beacons are a piece of hardware that emits BLE signal to a Bluetooth‐enabled receiver “which allows another device to determine its proximity to the broadcaster” . This advance in, or simplification of the Bluetooth technology has opened up many possibilities for small amounts of data to be transferred. This allows devices to communicate with one another, either with updates, commands, or other information, which we now refer to as IoT (see Figure 16.1).