Everything you need to know about MacOS Sierra

The operating system working behind the scenes on your computer is at least as important as the hardware itself, and that's especially true for Apple products, where the same company makes both the hardware and software.

For years, MacBooks and Mac desktops have run on the operating system Apple calls OS X. That's about to change, as as Apple has rebranded its computer software as MacOS, a new name more in line with iOS, WatchOS and TVOS.

New Macs should include the first version of MacOS, code-named Sierra, starting in the fall of 2016, while a public beta is expected in July. For now, this preview covers some of the new features included with the current developer's build (not available to the general public), as well as promised features coming to the final version.

Cleaning up space on a Mac is a lot easier

Space has always been an issue, especially if if you get a laptop with only 128GB of storage. With Optimized Storage, you can easily save some space with the click of a button. The trick here is that Apple is making use of iCloud and iCloud Drive. You can keep your watched iTunes content in the cloud and only save recent mail attachments on your physical drive. It will also automatically empty your trash after 30 days, and it has a new interface that displays a comprehensive list of what's taking up space on the hard drive and allows you to delete files in a snap.

Picture-in-picture is now built-in

The struggle of having to open a video in a new window and rearranging your desktop is over. Picture-in-picture is coming with MacOS Sierra -- it will be available within Safari and iTunes, as well as websites that use HTML5 video. In our testing, it has worked really well with Vimeo and ESPN. This will not be automatic for all websites, though. Apple is releasing a developer API that web developers can implement, so here's hoping that YouTube, Netflix, and Hulu will take advantage of this.

Messages is on a new level with rich links and tapbacks

All of those new Messages features from iOS 10 are making their way to the Mac. While you won't be able to send digital touches, invisible inks, stickers or handwritten message from the Mac, you can see them and interact with them if sent from an iOS device. But, the best feature out of Messages for the Mac will be those rich links, which includes being able to watch the video or read the first part of the story inline. With tapbacks you can provide your own quick color commentary on what people are sending you.

Apple Pay is on the Mac, but not physically

No, Apple is not putting NFC inside of all its hardware. Instead, websites that have Apple Pay integrated into checkout, like Shopify, will let you use your iPhone or Apple Watch to complete a transaction via the Mac. If your device is close by, the site will ask for authentication through your Apple Watch or iOS device.

iTunes has a small but helpful redesign

The look and feel of Apple Music continues to take over iTunes. Under Music, you now have menu options for library, "for you," browse, radio and the iTunes Store.

Desktop and Documents are now in iCloud

If you own multiple Macs, getting files from one device to the other will now be easier than ever. By checking off a new checkbox in the iCloud settings menu, files on the desktop or in the documents folders of multiple Macs can now be automatically synced. Drop a file or add a screenshot to the desktop of one MacOS system, and a few seconds later, it pops up on the other ones. The documents folder, the other place you're likely to store important files, works similarly, but each machine gets a named folder within the documents folder on its sister machines.

Photos is smarter and will curate your memories

Photos is the other application, besides iTunes and Messages, that's getting a big update in Sierra. For starters, using new identifying technologies, you can search for photos by subject. Similar to Google Photos or HTC's Zoe feature, Photos also has a feature called Memories, which pulls different sets of photos and makes a video or album out of them.

What you copy on your iPhone can be pasted on your Mac

Universal Clipboard is another one of those signature Apple features -- it just works out of the box, as long as both devices have the same Apple ID. This feature allows you to copy and paste across devices, so if you copy an image on your iPhone, you can paste it into a Keynote slideshow on your Mac, and the same goes for blocks of text or URLs.

You can unlock your Mac with your Apple Watch

If you own an Apple Watch, it will become even more useful with iOS 10 and MacOS. When wearing the Apple Watch, walk up to your Mac, and you can wake it from sleep without manually entering a password, because the Watch securely authenticates with the Mac.

Siri is now on the Mac

People have been waiting for this one. After all the rumors, it's now official. With MacOS Sierra, Siri will be on the Mac.

Instead of holding down the home button, you can click the dock icon, the button in the top-right corner, or by hitting function-space (as of now in the developer preview).

On the Mac, Siri can search the web for an image, then you can then drag and drop it into a document. Siri can also search for files, for example, finding all images with a specific word in the file name from the last week or month. One interesting bonus: you can use it to get the serial number and information from your hardware.

The new MacOS Sierra operating system will be launching this fall, but the developer preview is available now, and a public beta is coming in July.