Airplane mode is a setting on mobile devices that disable wireless connections and services. The setting gets its name from rules requiring that all cellular services be disabled while on an airplane.
Most mobile devices have this setting, identified by a small icon representing an airplane. While in airplane mode, all wireless services, including Wi-Fi, cellular and Bluetooth, are automatically disabled. This is to prevent signals from passenger's devices from disrupting the flight. As part of the preflight instructions, flight attendants generally remind passengers to enable airplane mode or turn devices off. Depending on the individual airline's policy, however, some of these services may be re-enabled while in flight.