If you would like to know whether your Mac can upgrade to the latest version of macOS, there is an easy way to check using Apple's special page on the subject. You can also jump right from that page to the Mac App Store page on Sierra.
While a lot of people are talking about major new additions to macOS Sierra, there are some minor new features as well. Take a look at some tiny features that may make a huge difference to some users.
A new feature in macOS Sierra and iOS 10 is the ability to collaborate with more than one person in the Notes app. You can create a note and then add other Apple IDs to share the note with. Each person can add and edit the note in real time, or as an ongoing collaboration.
With macOS Sierra you can use Tabs in more apps than just the Finder and Safari. Most Apple apps such as Pages, TextEdit, Keynote and Numbers support tabs, so you can have several documents open in the same window. Some third-party apps already support tabs. Others will most likely add compatibility in the future.
With macOS Sierra you can easily put your Documents and Desktop folders in iCloud Drive. This makes these folders available to all of your Macs and iOS devices. It syncs them effortlessly, so you essentially have the same Desktop and Documents folders on all of your Macs.
A very exciting new feature of the Photos app in macOS Sierra is the ability to search your Photos library for objects. For instance, you can search for 'boat' and it will show you pictures in your library that have a boat. Take a look at how this feature works.
Here's a preview of what Siri on the Mac will look like. The latest beta of macOS Sierra lets you use Siri for most things that you can do on iOS. In addition, you can search your files, photos, the Web and System Preferences. You can send messages and post to social media. You can save Siri answers to Notifications Center and multitask while Siri is on the screen.