iOS is Apple's proprietary mobile operating system that powers the iPhone, iPad, and iPod Touch, known for its intuitive user interface based on direct manipulation and multi-touch gestures. It offers a rich ecosystem through the App Store, robust security and privacy features, and seamless integration with Apple's hardware and services like iCloud, iMessage, and FaceTime. Key features include Siri, multitasking capabilities (especially on iPads), customizable widgets, and the recent addition of Live Activities and Focus Modes. Major iOS versions are released annually, with the current stable version being iOS 18, which introduced significant enhancements such as customizable Home Screens, a redesigned Photos app, and satellite messaging, with the latest update being iOS 18.4. The upcoming iOS 19 is rumored to bring further design changes and enhanced AI features through Apple Intelligence, continuing the evolution of this widely used mobile platform.