The Apple Watch will work with the iPhone 6, iPhone 6 Plus, iPhone 5, iPhone 5C, and iPhone 5S.
Apple has custom-designed its own S1 SiP (System in Package) to miniaturize an entire computer architecture onto a single chip.
Apple Watch comes with 11 watch faces ranging from traditional analog faces to new faces like Timelapse face; Astronomy face with its interactive, real-time 3D model of the earth, sun, moon and planets; and the Solar face, a contemporary sundial.
Apple Watch can be personalized in appearance.
According to Apple, the user can reply to texts via voice reply or emoji.
'The Apple Watch understands questions in messages and then offers preselected answers.'
The feature lets the user respond to messages, and with Handoff, he can start a message on the Apple Watch and continue on the iPhone
Apple has introduced the WatchKit, which provides new tools and APIs for developers to create experiences designed for the wrist.'With Apple Watch, developers can create WatchKit apps with actionable notifications and Glances that provide timely information. Starting later next year, developers will be able to create fully native apps for Apple Watch,' Apple says.
The mobile wallet Apple Pay will also work with Apple Watch.
Apple Pay allows consumers to use iPhones linked to credit cards for more secure, convenient payments. Apple Pay is built into all the iPhone 6 and iPhone 6 Plus phones and all the devices will have a secure element chip, for apple pay service.
Apple Watch has infrared and visible-light LEDs, along with photosensors, to detect pulse rate.
The price of Apple Watch starts at $349 and will be available early next year.