what is watchos?
WatchOS is the operating system (OS) that runs on every Apple Watch - basically, the watch equivalent of iOS, which you'll find on iPhones and iPads. Operating systems essentially sit between the hardware - in this case, the Apple Watch - and the apps that you download. Everything that you do on your Watch is possible because of WatchOS. It's the menus that you scroll through, to load up apps and tweak the Watch's settings. It's the clock faces and other built-in features that you see when you turn your Watch on.