macOS Sierra (version 10.12 ... the update will be available free of charge from the Mac App Store, just like past versions of OS X.

Wondering which versions of macOS your Mac can run? We’ve put together a macOS compatibility checker that will show you what Macs the different versions of macOS and Mac OS X support ...

At its 2016 World Wide Developer Conference, Apple showed off some of the new features that will be coming to the macOS (formerly OS X) later this year. We can't wait to get our hands on them.