Stands for "Wireless Personal Area Network." A WPAN is a specific type of PAN (Personal Area Network) in which all the connections are wireless. It may use multiple types of wireless connections, but the most common is Bluetooth.
The "personal" aspect of a WPAN means it is meant to be used by a specific individual. For example, you might have a smartphone and smartwatch that communicate with each other. These devices securely transmit encrypted information back and forth, such as activity data, text messages, and alerts. The WPAN provides consistent communication between the devices and prevents the data from being shared with devices outside the network.
While most WPANs communicate over Bluetooth, devices may also transfer data over Wi-Fi. For example, a laptop may connect to a smartphone via Wi-Fi to make and receive calls. A tablet may sync with a smartphone over a home Wi-Fi network. In some cases, other radio frequencies or infrared signals may also be used.
Since WPANs are wireless, they are simple to set up and maintain. Once devices are paired using Bluetooth, they can automatically discover each other when in range, typically within 30 meters. A low-energy version of Bluetooth, called BLE, is often used to locate paired devices and establish connections between them. Data transfers, which require a stronger signal, take place over standard Bluetooth or Wi-Fi.