Apple just unveiled its latest smartwatch, the Apple Watch Series 3 — here's everything you need to know (AAPL)

At its annual event on Tuesday to unveil its latest hardware products, Apple launched its third-generation Apple Watch — the first with cellular built in. The watch can make and receive calls, allowing you to leave your phone at home. The Series 3 watch will have the same number as your iPhone.

"Now you have the freedom to go anywhere with just your Apple Watch," said Apple's chief operating officer, Jeff Williams. "This has been our vision since the very beginning."

The watch will be available to order on Friday and will start at $329 — the watch with cellular will cost $399. It will be available a week later, on September 22.

The new watch comes in three colors: a new gold aluminum finish, silver, and space gray. The new Apple Watch Edition, the premium version that has a ceramic case, will come in a new gray finish (the previous version came only in white).

Here are the features of Apple Watch Series 3:

The Apple Watch Series 3 will run WatchOS 4, Apple's smartwatch operating system, which arrives Friday. WatchOS 4 will have Siri built in, and it will be able to handle person-to-person payments using Apple Pay. It will have smart activity coaching, a redesigned workout app, and more.

Apple's most recent smartwatch, the Apple Watch Series 2, was released a year ago and featured a faster processor than the original, GPS tracking, and the ability to wear it while swimming.

The Apple Watch Series 1 and 2, which are still available to buy, come in rose gold, space gray, and gold. The Series 1 starts at $269, while the Series 2 starts at $369. The Series 2 also comes in stainless steel and space black, both of which start at $549.

The Apple Watch Edition has a white ceramic case and starts at $1,249.

Apple says sales of the Watch grew by 50% last quarter compared with the previous year and that it's now "the No. 1 watch in the world." While Apple doesn't release official sales figures, analysts estimate that Apple shipped 4.6 million Apple Watches during the 2016 holiday quarter.