MacOS High Sierra 10.13.6 vs MacOS Catalina 10.15.7
I am currently using MacOS High Sierra 10.13.6 on my MacBook Air 13" mid 2012 4 GB. I no longer receive software updates as MacOS Catalina 10.15.7 is the only available upgrade supported. I am concerned about any negative impacts downloading Catalina 10.15.7 would have and whether FIrefox 87.0 (64-bit) is able to support MacOS Catalina 10.15.7. Any thoughts? Thank you for your time and efforts.