Much of the iPhone’s success can be attributed to Apple’s ability to keep the product competitive throughout the years, with new releases and updates. iPhone sales jumped from around 40 million units sold in 2010 to more than 210 million iPhones sold in 2016 alone, which translated into more than 54 billion U.S. dollars in revenue for Apple during the fourth quarter of 2016 alone. As sales increased, the iPhone's importance to the company's success increased, changing Apple’s business dramatically and becoming the most successful Apple product. The iPhone’s share of the company’s total revenue has jumped from around one third in 2009 to about two thirds of the overall revenue in 2016.
The iPhone runs on Apple’s own mobile operating system, iOS, which is the second most popular smartphone operating system in the world. Each of the nine iPhone generations introduced to the market was accompanied by a major release of Apple’s iOS. For browsing and downloading applications to the iPhone, the user has to go through the Apple App Store, which has more than two million mobile apps available. Games, business and education are the top three most popular app categories in the Apple App Store, with games accounting for about a quarter of all active apps on the platform.