Activation Lock
Activation Lock helps prevent anyone else from using your device if it’s ever lost or stolen. When you turn on Find My [device] on an iPhone, iPad, Mac, or Apple Watch, Activation Lock is turned on automatically.
With Activation Lock, your Apple Account password is required before anyone can do the following:
Turn off the Find My [device] setting on your device
Sign out of iCloud on your device
Erase and reactivate your device
See any of the following Apple Support articles: