Operating system upgrade
Please can one upgrade Mac OS Mojave and Yosemite? To what can one upgrade to?
Question marked as
That depends on which Mac and which model year, and which upgrade you’re planning...
If you have a MacBook Pro:
Identify your MacBook Pro model - Apple Support
Details for the usual upgrades:
How to upgrade to macOS Catalina - Apple Support
How to upgrade to macOS Mojave - Apple Support
How to upgrade to macOS High Sierra - Apple Support
How to upgrade to OS X El Capitan - Apple Support (wouldn’t bother with Yosemite...)
Going from Mojave to Yosemite is a wipe and start over. There’s no downgrade. This assumes that the particular Mac supports Yosemite, which any recent Mac won’t.
Whatever you pick, have backups.