Apple Watch is a line of smartwatches developed by Apple Inc. It incorporates fitness tracking and health-oriented capabilities with integration with iOS and other Apple products and services. The original generation of the device was available in four variants: Apple Watch Sport, Apple Watch, Apple Watch Hermès, and Apple Watch Edition; each distinguished by different combinations of cases and first- or third-party interchangeable bands. Apple Watch relies on a wirelessly connected iPhone to perform many of its default functions such as calling and texting. It is compatible with the iPhone 5 or later models running iOS 8.2 or later, through the use of Wi-Fi or Bluetooth. Announced by Apple CEO Tim Cook in September 2014, the device was released in April 2015. The Apple Watch quickly became the best-selling wearable device with the supply of 4.2 million smartwatches in the second quarter of the 2015 fiscal year. The second generation of Apple Watch, released in September 2016, includes two tiers: Apple Watch Series 2 and Apple Watch Series 1, which includes the S1P chip, but is otherwise identical to the original.The goal of the Apple Watch was to enhance the uses of an iPhone by using a watch. Kevin Lynch was brought on by Apple to make wearable technology for the wrist. He said: "People are carrying their phones with them and looking at the screen so much. People want that level of engagement. But how do we provide it in a way that's a little more human, a little more in the moment when you’re with somebody?" The Apple Watch works by connecting via Bluetooth to the phone and accessing any Watch compatible apps stored on the mobile device. Apple's development process was held very much under wraps until a Wired article revealed how some internal design decisions were made.
I. APPLE WATCH FIRST GENERATION
The first-generation Apple Watch uses the S1 system-on-chip. It does not have a built-in GPS chip, instead relying on a paired iPhone for location services. It uses a linear actuator called the "Taptic Engine" to provide haptic feedback when an alert or a notification is received, and is used for other purposes by certain apps. The watch is equipped with a built-in heart rate sensor, which uses both infrared and visible-light LEDs and photodiodes. All versions of the Apple Watch have 8 GB of storage; the operating system allows the user to store up to 2 GB of music and 75 MB of photos. When the Apple Watch is paired with an iPhone, all music on that iPhone is also available to be controlled and accessed from the Apple Watch. The Apple Watch only turns on when you activate the watch (either by lifting your wrist, touching the screen, or pressing a button). The hardware has a large number of proprietary and custom accessories available for a customized look. Third-party bands and cases can be switched at the user's discretion.
II. APPLE WATCH SECOND GENERATION
The second generation has two tiers. One, Series 1 has a dual-core variant of the Apple S1 processor, dubbed S1P, and has a lower starting price than first generation watches. The other, Series 2, has a dual-core Apple S2 processor, adds ambient light sensor, water resistance to 50 meters, a 2x brighter display (1000 nits vs 450 nits), as well as GPS.
