Apple Watch is a line of smartwatches by Apple Inc. that connects to iOS & other Apple products/services. It features fitness tracking, health monitoring, and wireless connectivity. Apple debuted the first Apple Watch in 2015, quickly becoming the best-selling wearable device. By 2020, over 100 million people are expected to own an Apple Watch. New generations are released each September, with variants defined by casing material, color, and size, and starting with Series 3, with the option of LTE cellular connectivity. Bands can be selected from Apple's options, and there are also co-branded watches with Nike and Hermès.