The operating system used on an iPhone is __________.

iOS is the iPhone's only operating system. There is no iPhone OS or Windows for iPhone. Google created the Android operating system, which is used on smartphones, tablets, and other touchscreen devices, except for Apple's products. Other operating systems include iPadOS, which is only used and found on iPads, as well as Windows, Linux, and macOS, which are available on desktop and laptop PCs, and Chrome OS, which is proprietary and found on Chromebooks.