What is the meaning of IOS in Operating System category?

iOS is a mobile operating system created and developed by Apple Inc. It is the second most popular mobile OS after Google's Android. The iOS operating system is created to run specifically on Apple hardware and machines. Apple uses iOS as the operating system in it's various products, including iPhone, iPod, and iPads. The first version of iOS was introduced to the world at the Macworld Conference & Expo on January 9, 2007, it was later released on June 29, 2007. Various power packed features proovided by iOS are: Home screen, System font, Folders, Notification Center, Accessibility, Multitasking, Switching applications, Ending tasks, Task completion, Siri, and Game Center.