What is the difference between Big Sur and Monterey for the MacBook Pro?

Just be a bit careful. If you use Photos and try Monterey, but go back to Big Sur, the changes Monterey makes to your Library will prevent Big Sur's Photos from opening it.

That can be true of almost all of Apple's data Libraries, Music, Mail, Photos, etc. They don't always change, but they quite often do. When that happens, you can't go backwards. If you don't have a previous backup, you have to export the data from the working OS version and then import back into the older data store, losing keywords and other metadata stored in the Library.

Here’s what is new. If you think the new features would be useful, then you might want to upgrade.

If you have apps that won’t work in Monterey, and you cannot replace them, then maybe you don’t want to upgrade.

Tips Monterey Upgrade 

Tips Big Sir Upgrade

Just be a bit careful. If you use Photos and try Monterey, but go back to Big Sur, the changes Monterey makes to your Library will prevent Big Sur's Photos from opening it.