Apple Watch will automatically lock whenever the user takes off the watch as sensors on its backside detect when it's not being worn and locks down the payment options behind a passcode as a security measure.

The watch also has ‘Find my Apple Watch’ security that allows users to remotely wipe their smartwatch.

Apple Inc on Tuesday entered the market of wearable device with the launch of its long-anticipated smartwatch tethered to the iPhone that will combine health and fitness tracking with communications.

Priced at USD 349, the Apple Watch sports a flat screen with sapphire glass and has a 'digital crown' with a twisting control that lets the user scroll through different functions. It runs apps, takes dictation and interacts with the iPhone.
"With the Digital Crown, you can scroll, zoom, and navigate Apple Watch without covering the display," Apple said.
The watch has a gyroscope and an accelerometer that measures fitness. Besides, it uses the GPS and Wi-Fi in the users' iPhone to help track the distance.
It comes with colorful wrist bands (pink, blue and white) and styles like hand-crafted gold buckle.
Apple said: "Apple Watch will start at USD 349 and will be available early next year. It works with iPhone 5, 5c, 5s, 6, and 6 Plus."
The smartwatch has three variants -- Apple Watch, Apple Watch Sport, and Apple Watch Edition, which is made from 18-karat gold.

Starting at USD 349 – USD 50 more than the cheapest version of the iPhone 6 with a contract, the lofty price tag may also keep some consumers on the sidelines. It could go up to more than USD 1,000 for higher-end editions, IDC analyst Danielle Levitas said.

It's the first new product to be developed and introduced under Chief Executive Officer Tim Cook's reign, the next chapter in Apple's history.

Apple unveiled a mobile payments service along with a watch to revive the technology company's reputation as a wellspring of innovation.

"Apple Pay will work with the three major payment networks: American Express, MasterCard, and Visa. Apple Pay will be available in the US in October 2014. And work is underway to take it worldwide in the near future," Cook said.
With Apple Pay, users will be able to check out with one tap, making purchasing through apps easier, more secure, and private.
Merchants like Target, Groupon are already on board, with others like Disney, Chipotle, and coming in by the end of the year.
Each phone will come equipped with its new payments service, which launches in the United States next month and allows users to pay for items in stores with their phones instead of physically presenting their credit or debit cards.
Launch partners include Walt Disney Co, McDonald's  and Whole Foods. The move gives Apple access to a trove of data on how consumers shop in brick and mortar stores, where more than 90 percent of U.S. retail sales are still conducted.
Each new iPhone will come with a "secure element" chip and a near-field communications, or NFC, antenna.
Ben Milne, CEO of Internet payment network Dwolla, wanted to hear a lot more about how Apple will tackle the aging payments infrastructure. Apple Pay should get some level of mass adoption based on the number of iPhones out there, but Apple will have to tackle the current high costs of payment processing to make its new feature more widespread.
"The old architecture that payments are driven on is not up to snuff for the future they want to build," Milne said.