Questo è chiamato consegnato
Ti consente di continuare dove ti sei interrotto in un'app su un dispositivo quando accedi a un altro dispositivo.
Funziona tramite l'AppleID e non l'utente locale.
When your Mac computers and iOS devices are within Bluetooth range of
each other (about 33 feet or 10 meters), they can automatically “hand
off” what you’re doing from one device to another. For example, you
can start writing an email in Mail on your iPhone, then instantly pick
up where you left off in Mail on your Mac.
Handoff app icon in Dock Handoff works with several apps that come
with OS X Yosemite and iOS 8: Calendar, Contacts, Mail, Maps,
Messages, Notes, Phone (iOS only), Reminders, and Safari. It also
works with Keynote v6.5, Numbers v3.5, and Pages v5.5 for Mac, and
Keynote, Numbers, and Pages v2.5 for iOS. Third-party apps may also
work with Handoff.
Puoi disattivarlo sotto il riquadro delle preferenze generali in Preferenze di Sistema