A beacon is a device that alerts mobile devices, such as smartphones and tablets, of its presence through radio waves under the Bluetooth 4.0 protocol well known as Bluetooth Smart or Bluetooth Low Energy (BLE).

A beacon device broadcasts a small quantity of information, called frames, every so often. When a mobile device is close enough and receives this information, if an app recognizes it as its own, then, a specific action can be triggered by:

1. Proximity: it depends on the distance to a beacon.
2. Area: an action is triggered on entering or exiting a region area.

The main applications are:

• To help business send target offers to their customers.
• To provide more information when a user is in an interesting place (like museums).
• To collect sensor data (weather stations, motion detectors, buttons, etc.).
• To create indoor heat maps to understand your customer’s behavior better.