Final answer:
Beacons commonly use Bluetooth to communicate with an application on a customer's phone.
Step-by-step explanation:
Beacons commonly use Bluetooth to communicate with an application on a customer's phone. Bluetooth is a wireless technology that allows devices to connect and exchange data over short distances. In this case, the beacon would transmit a signal using Bluetooth to the customer's phone, which would then receive and interpret the signal using the corresponding application.