AirDrop is an ad-hoc service in Apple Inc.'s macOS and iOS operating systems, introduced in Mac OS X Lion (Mac OS X 10.7) and iOS 7, which enables the transfer of files among supported Macintosh computers and iOS devices without using mail or a mass storage device. 

How to Turn on AirDrop? 

Use Control Center to turn AirDrop on or off and control whom you can share content with.

Step 1: Swipe up from the bottom of your screen to open Control Center.

Step 2: Tap AirDrop.

Step 3: Choose one of these options:

* Receiving Off: Turns off AirDrop.

* Contacts Only: Only your contacts can see your device.

* Everyone: All nearby iOS devices using AirDrop can see your device.