The new OS upgrade, Monterey is not compatible with one of my Macs, a late 2013 27' iMac.
iMac 27″, macOS 10.12
Just to add to what Bob stated, the latest version of macOS you can run on a Late 2013 is Catalina 10.15.7. If you haven't upgraded you may want to do so. Just be aware older 32bit apps will no longer run so you need to check using Go64 if you have any installed that may need updated or replaced.
To get Catalina, see this page: How to download macOS - Apple Support
Just to add to what Bob stated, the latest version of macOS you can run on a Late 2013 is Catalina 10.15.7. If you haven't upgraded you may want to do so. Just be aware older 32bit apps will no longer run so you need to check using Go64 if you have any installed that may need updated or replaced.
To get Catalina, see this page: How to download macOS - Apple Support
Your 2013 computer will continue doing what it is doing. If you want/need the newest MacOS you will need to purchase a new computer.
Mostly you just need a more modern Browser than Safari on Mojave, or High Sierra like Firefox or Brave.
Regarding Monterey, what should I do with my Late 2013 27' iMac
