Quick Answer: The iPhone is a line of smartphones developed and marketed by Apple that run iOS, the company's own mobile operating system. The first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at Macworld 2007, and launched later that year. Since then, Apple has annually released new iPhone models and iOS versions; the latest models being the iPhone 17, the higher-end iPhone 17 Pro and 17 Pro Max, and the thinner iPhone Air. As of July 2025, more than 3 billion iPhones have been sold, and Apple has been the largest vendor of mobile phones since 2023. The original iPhone was the first mobile phone to use multi-touch technology. Throughout its history, the iPhone has gained larger, higher-resolution displays, video-recording functionality, waterproofing, and many accessibility features. Up to the iPhone 8 and 8 Plus, iPhones had a single button on the front panel, with the iPhone 5s and later integrating a Touch ID fingerprint sensor.