Definition - What does Cisco IOS mean?
Cisco IOS (Internetwork Operating System) is a software made by Cisco for use on various hardware devices such as networking routers and switches. A command-line interface governs a series of “trains” defined as tools for delivering Cisco software to specific platforms.
Techopedia explains Cisco IOS
Cisco defines Cisco IOS as “the world's leading network infrastructure software,” contending that, by delivering a seamless integration of platform support and business services, this operating system is a versatile resource for diverse types of networking. Cisco also calls IOS as the most widely used software of its kind anywhere in the world.
In general, Cisco IOS represents a modern operating system for handling network hardware for a household name in advanced networking technology. Cisco IOS also features an easy syntax such as "show, copy, config and debug" commands and the use of a question mark (“?”) to access help features.