AirDrop

AirDrop is a Bluetooth feature introduced in 2013 alongside iOS 7. It can be accessed and managed through Control Center.

AirDrop in Control Center
When you manage AirDrop in the Control Center, upon clicking the AirDrop icon, 3 options will show up: "Recieving Off", "Contacts Only" and "Everyone". Contacts Only restricts anyone except your contacts to AirDrop anything to you. Recieving Off closes AirDrop completely.