Apple Watch is a line of smartwatches produced by Apple Inc. It incorporates fitness tracking, health-oriented capabilities, and wireless telecommunication, and integrates with iOS and other Apple products and services.
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. In subsequent years, a new generation of Apple Watch with an improved set of internal components — labeled by Apple a 'Series', with certain exceptions — has been introduced each September.Each Series has been initially sold in multiple variants defined by the watch casing's material, color, and size (except for the budget watches Series 1 and SE, available only in aluminum), and beginning with Series 3, by the option in the aluminum variants for LTE cellular connectivity, which comes standard with the other materials. The band included with the watch can be selected from multiple options from Apple, and watch variants in aluminum co-branded with Nike and in stainless steel co-branded with Hermès are also offered, which include exclusive bands and digital watch faces carrying those companies' brandings.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 independently 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. The oldest model of iPhone that is compatible with any given Apple Watch depends on the version of system software installed on each device.