Smartphone is a cellular telephone that also works as a small computer. Smartphones are the most popular kind of personal computer. Billions of people throughout the world have smartphones, more than have desktop or laptop computers. Modern smartphones almost always feature a touch screen and one or more cameras, microphones, and speakers. Smartphones pair these features with a connection to an advanced cellular network to enable the user to make calls, read articles, or play electronic games without being connected to a landline. The technology companies Apple and Samsung manufacture the most popular smartphones.
Like other computers, a smartphone uses a specialized operating system (OS). An OS is the primary computer program that controls the rest of the phone’s features. The OS also determines the kinds of apps (applications) that a user can install on the phone. The two most popular smartphone operating systems are Apple’s iOS and the open-source Android.
Modern smartphones trace their roots to cellular phones that—in addition to making calls—enabled the user to perform such basic tasks as playing simple games, saving contact information, or checking email. Such cellular phones were called feature phones. Feature phones had greater functionality than simple cell phones, but they were limited by push-button interfaces, limited cellular network capacity, and small selections of programs.
The Canadian firm Research in Motion released its first BlackBerry device with telephone capabilities in 2002. BlackBerry was a series of early smartphones that gained wide popularity in the business sector. BlackBerry devices had small, built-in, typewriter-style keyboards to enable the user to quickly compose emails. In feature phones, users had to repeatedly press number keys to select individual letters. Other companies, such as Motorola, Inc. (now called Motorola Solutions, Inc.), Nokia, and Palm, produced smartphones similar to the BlackBerry. Many of these phones used an OS called Symbian.
Apple released the iPhone in 2007. It featured a touch-sensitive screen and combined a wireless phone, a music and video player, and mobile internet and email capabilities. The high-quality touch screen, which could distinguish among different types of touch, enabled designers to greatly reduce the number of buttons on the phone. A keyboard appeared on the lower half of the touch screen for composing messages and other typing tasks, but it disappeared when not in use. The iPhone used Apple’s proprietary operating system. 
Apple launched the App Store in 2008. The App Store allowed iPhone users to download apps created by Apple and other developers. The iPhone’s portability, built-in cameras, and touch screen enabled programmers to create entirely new kinds of apps, such as photography filters, touch screen-based games, and interactive maps. The iPhone’s easy-to-use interface, combined with the integration of Apple’s popular music system iTunes, made the device extremely successful.
Some executives at Google feared that Apple would prevent Google’s online products from being used on the iPhone. Such an action would prohibit Google from generating advertising revenue from iPhone users. Google had been developing the Android OS since 2005. After the iPhone was released, Google quickly redesigned it for touch screen-based smartphones.
Before the iPhone was released, Apple signed a multi-year agreement to sell it exclusively to customers of the cellular carrier AT&T in the United States. Google convinced other carriers and phone manufacturers to build and sell smartphones with the Android OS to compete with the iPhone. The first smartphone to use Android was released in 2008. Android quickly became the OS of choice for all non-Apple smartphone manufacturers. Android usually comes packaged with Google apps, including an app marketplace called Google Play.
