Normally when you set up your iPhone sync Mac, you will be asked if you want to erase and replace the data on your phone with the data on that computer, which may not be ideal every time. That means, if you want to share files between your iPhone and more than one Mac - say while you’re on campus, collaborating at the office, or visiting a friend - you will have to use a third-party app, email, a cloud service or other workarounds to share and sync files.
The change is pretty minor since it’s the same interface just in a different app, but one thing remains the same: you can only sync your iPhone to one Mac computer.
Syncing iPhone to Mac with macOS Big Sur is now done through Finder instead of iTunes.
