Apple ID Support
http://www.apple.com/support/appleid/
An Apple ID is the account you use to access Apple services
like iCloud, the App Store, the iTunes Store, Apple Music,
and more. It includes the email address and password that
you use to sign in, and all the contact, payment, and
security details that you'll use across Apple services.
No matter where you create your Apple ID, just remember to
use the same one to sign in to every Apple service. That
way, you can access and manage everything with a single
account and password.
Multiple Apple IDs just leads to multiple problems
http://www.macworld.com/article/3125475
Reset (Forgotten) Apple ID Password
https://support.apple.com/en-us/HT201355
https://support.apple.com/en-us/HT201487
Reset (Forgotten) macOS Computer Password
https://support.apple.com/guide/mac-help/reset-your-mac-login-password-mh35902/mac
https://support.apple.com/en-us/HT202860
Boot (Command-R) > Utilities > Terminal, type: resetpassword
Reset (Forgotten) passcode for your iPhone, iPad, or iPod-touch
https://support.apple.com/en-us/HT204306
Contacting Apple
http://www.apple.com/contact/
800-MY-APPLE (800-692-7753)
Find My (all your Apple devices using the same Apple ID)
Demo Find My iPhone (or iPad, iPod or Mac)
iCloud & iCloud Drive
http://www.apple.com/icloud/
http://support.apple.com/kb/PH2608
https://www.icloud.com
iCloud mostly serves to back up your device and sync limited
kinds of data to other Apple devices, while iCloud Drive
more focuses on sharing among devices and seamless
interaction and co-working among devices, which means that
data in one device can be shared among other devices without
copying, sending or transferring. For example, you create a
new Pages file on your MacBook Air, put a few lines on it,
and then throw it into iCloud Drive. Then you may continue
working on it wherever you go as long as you have access to
it via your iPhone or iPad.
What does iCloud back up?
https://support.apple.com/en-us/HT207428
iCloud Security
https://support.apple.com/en-us/HT202303
E2EE (End-to-end encrypted data)
https://support.apple.com/en-us/HT202303
End-to-end encryption provides the highest level of data
security. On each of your devices, the data that you store
in iCloud and that's associated with your Apple ID is
protected with a key derived from information unique to that
device, combined with your device passcode which only you
know. No one else, not even Apple, can access end-to-end
encrypted information.
Access and manage files in your iCloud Drive
https://support.apple.com/en-us/HT201104
sam.wormley@gmail.com