AirDrop
AirDrop is a proprietary wireless "ad hoc" service to share files between Apple devices. It is notoriously unreliable, but is very nice when it works.
On modern Apple devices, AirDrop uses Bluetooth for discovering other nearby devices. When two AirDrop devices agree to connect, they form a direct wireless connection between each other to transfer files. AirDrop does not use the District Wi-Fi.
AirDrop requires some device configuration on both ends to get working. The articles below should help.
Helpful Links
Use AirDrop on your Mac: https://support.apple.com/en-us/102538
How to use AirDrop on your iPhone or iPad: https://support.apple.com/en-us/HT204144
What is AirDrop and How Does It Work?: https://www.lifewire.com/what-is-airdrop-how-does-it-work-1994512