It’s a common problem of the modern age: how to share just enough with a partner or with your family, but not your personal stuff, like emails and messages. An Apple ID is designed to be a unique identifier you can use across all Apple services and purchases, but Apple recognized that for legacy and other reasons, it had to separate iCloud-connected stuff, iMessage and FaceTime, and iTunes Store and various App Stores purchases.
If you simply share the same Apple ID among everyone, as one Macworld reader discovered, all your private communication and information appears for all devices (and people) logged into the same account. Instead, you split up roles within iOS and macOS by account.
