iOS - Wikipedia
https://en.wikipedia.org/wiki/IOS
iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that presently powers many of the company's...
Download iOS Firmware for iPhone, iPad, iPod... / IPSW Downloads
https://ipsw.me/
IPSW Downloads. Download current and previous versions of Apple's iOS, iPadOS, watchOS, tvOS and audioOS firmware and receive notifications when new firmwares are released.
iOS | Apple Wiki | Fandom
https://apple.fandom.com/wiki/IOS
iOS (formerly iPhone OS) is a mobile operating system from Apple Inc. Originally developed for the iPhone, it has since been extended to support other Apple devices including the original Apple TV, iPod Touch and iPad.
Download iOS Firmware for iPhone, iPad, iPod, and Apple TV
https://iosindex.com/
Provides direct download link of current and previous version iOS firmware (.ipsw) for iPhone, iPad, iPad Mini, iPad Air, iPod Classic, iPod Touch, iPod Nano, iPod Shuffle, and Apple TV.
What Is iOS? (iPhone Operating System)
https://www.lifewire.com/what-is-ios-1994355
Formerly known as the iPhone OS, iOS is Apple's mobile operating system that runs the popular iPhone, iPad, and iPod Touch mobile devices.
What is Apple iOS? Webopedia Definition
https://www.webopedia.com/TERM/A/apple_ios.html
Apple iOS is currently in v10.x release, with iOS10 first being introduced at the company's 2016 Worldwide Developers Conference (WWDC) in early June 2016.