Set up iCloud Keychain to autofill information on Mac
iCloud Keychain keeps the website login information and credit card information that you use with autofill in Safari, and your Wi-Fi network information up to date across your Mac, iPhone, and iPad.
iCloud Keychain also stores account settings, so your social media accounts can be added automatically to another Mac when you sign in to your Apple Account on that Mac. For example, Exchange, Google, and other internet accounts you use with Mail, Contacts, Calendar, Reminders, Notes, and Messages can be added automatically.
Everything stored in iCloud Keychain is secure—it’s protected by industry-standard encryption.
Your iCloud Keychain can’t be set up on another Mac, iPhone, or iPad unless you approve it.