Smartwatch created by Apple, Inc.
The Apple Watch operates primarily in conjunction with the user's iPhone for functions such as configuring the watch and syncing data with iPhone apps, but can separately connect to a Wi-Fi network for some data-reliant purposes, including basic communications and audio streaming. LTE-equipped models can connect to a mobile network, including for calling, texting, and installed mobile app data use, substantially reducing the need for an iPhone after initial setup. Although the paired iPhone need not be near the watch, to make a call with the watch, the paired iPhone must still be powered on and connected to a cellular network. The oldest iPhone model that is compatible with any given Apple Watch depends on the version of system software installed on each device. As of September 2021, new Apple Watches come with watchOS 8 preinstalled and require an iPhone running iOS 15, which is available for the iPhone 6S and later.
The Apple Watch was released in April 2015 and quickly became the best-selling wearable device: 4.2 million were sold in the second quarter of fiscal 2015, and more than 100 million people were estimated to use an Apple Watch as of December 2020. Apple has introduced new generations of the Apple Watch with improved internal components each September—each labeled by Apple a 'Series', with certain exceptions.