Io, IO, I/O, i/o, or i.o. may refer to:
Iowa () is a U.S. state in the Midwestern United States, bordered by the Mississippi River on the east and the Missouri River and the Big Sioux River on the west.
iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware.
iOS jailbreaking is the process of removing software restrictions imposed by Apple on iOS and tvOS. It does this by using a series of software exploits.
iOS is a mobile operating system, developed by Apple Inc. for iPhone, iPad, and iPod Touch. Updates for iOS are released through the iTunes software, and, since iOS 5, via over-the-air software updates.
An ion thruster is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions with electricity.
Ion Television is an American broadcast, cable, and satellite television network that is owned by Ion Media Networks.
iOS 10 is the tenth major release of the iOS mobile operating system developed by Apple Inc., being the successor to iOS 9. It was announced at the company's Worldwide Developers Conference on June 13, 2016, and was released on September 13, 2016. It will be succeeded by iOS 11, which was announced on June 5, 2017.