1. Originally known as the iPhone OS, the iOS is the name of the operating system that runs on Apple iPhone, Apple iPad, and Apple iPad Touch devices given to the devices by Steve Jobs during the 2010 WWDC. The iOS is one of the most used platforms for mobile devices, only slightly edged out by Android from Google.
2. Short for Input/Output Supervisor, IOS is a program developed by Microsoft that watches over the interaction of the file system and computer drivers.
3. Short for Internetworking operating system, IOS was developed by Cisco and is used to manage and control network routers, switches, and other network devices.