The Apple Watch combines a suite of sensors with an innovative interface to provide a new computing experience on the wrist.
Combined with an iPhone 5 or later (required), the Apple Watch provides fitness data and personal tracking information as well as time and other functions.
The Watch’s force-sensitive retina display can distinguish between a tap and a press. A sapphire cover protects the screen. The Watch has a digital crown that is turned and pushed to manipulate the watch interface.
A sensor on the back of the case uses infrared and visible-light LEDs and photodiodes to detect the wearer’s heart rate. A feature inside the watch called the “Taptic Engine” produces haptic feedback (taps) to provide tactile and customizable alerts and notifications without sound or vibration.
The watch incudes apps to track daily movement as well as specific workout routines, utilizing its sensor and also sensors on the user’s iPhone.
Source:LiveScience