I always thought people had to pay for every update and upgrade, this company being apple, but just yesterday I found out the upgrade from 10 to 11 is free (don’t know about an upgrade from 11 to 12, are upgrades to the newest and still supported macOS version free?)

What other applications do macOS users get for free?

Do macOS users get more free apps if they create an account with apple?

I’ve understood adobe and MS-Office are active at the mac app store. How does apple’s business model work? Do I buy the app, pay once and get free updates and upgrades indefinitely? or do I have to pay them a monthly fee?

Can LibreOffice be used on a macOS?

Is there an emulator to use ubuntu or windows based apps on a mac? Are they free of charge?