software upgrade .
my mac mini is running on high sierra and i want to upgrade to the latest version kindly help me.
Mac mini, macOS 10.13
Backup your data before you upgrade to anything.
We need a little more info before we can tell you what you can upgrade to:
Apple menu -> About This Mac -> System Report will give you your Machine ID under the hardware.
The Machine ID must be a minimum of 6,x to upgrade to 10.14.6 or 10.15.7, and a minimum of 7,x (x can be any number) to upgrade to 11.3.1
Otherwise the latest you can upgrade to is 10.13.6's latest security update, and Safari is no longer current.
Apple menu -> About This Mac will tell you if you are already running 10.13.6. If you aren't, click on the link for 10.13.6 before installing the security update. Other links explain how to upgrade each one, and what browsers you can use instead.