The iPhone is a line of touchscreen-based smartphones designed and marketed by Apple Inc. All generations of the iPhone use Apple's iOS mobile operating system software. The first-generation iPhone was released on June 29, 2007, and multiple new hardware iterations with new iOS releases have been released since.
The first-generation iPhone was described as "revolutionary" and a "game-changer" for the mobile phone industry. Subsequent iterations of the iPhone have also garnered praise. The iPhone is one of the most widely used smartphones in the world, and its success has been credited with helping Apple become one of the world's most valuable publicly traded companies.
As of November 1, 2018, more than 2.2 billion iPhones had been sold.