What is iOS you ask? Simply put it is the operating system that the iPhone, iPad, Apple TV(as of 2nd Gen) and iPod run off of. This is Apples mobile operating system and has been actively part of the mobile universe since it came packaged on the 1st generation iPhone back in 2007.
iOS runs off of Objective-C programming and utilizes Cocoa and Cocoa Touch. Recently Apple has released SWIFT a new programing language to work with Cocoa and Cocoa Touch. If you are interested in developing your own apps take a look at SWIFT on Apples dev site here Click Me for more info on SWIFT.
Curious about expanding what IOS can do on your device look into jailbreaking. Not sure what Jailbreaking is? find out here “What is Jailbreaking”.