Do icloud services work on mac devices that don't support Big Surr?

Question

macOS

Actually a subject. I just can’t decide on a purchase, so far I’m trying to consider the issue from all sides, with an attempt at foresight.
Interested primarily in organizational applications: Calendar, Notes, Tasks and Contacts.
And where in general can you see which applications will be limited, perhaps AirDrop will not work?
Sorry, but I could not find sane information on the Internet.

Answer 1

https://support.apple.com/en-us/HT204230