iPhone is a line of smartphones designed and marketed by Apple. It runs Apple’s iOS mobile operating system. The first generation iPhone was released in 2007; the most recent iPhone models are the iPhone 6 and iPhone 6 Plus, which were released in 2014. The user interface is built around the device’s multi-touch screen, including a virtual keyboard. The iPhone has Wi-Fi and can connect to many cellular networks. An iPhone can shoot video (though this was not a standard feature until the iPhone 3GS), take photos, play music, send and receive email, browse the web, send texts, GPS navigation, record notes, do mathematical calculations, and receive visual voicemail. Other functions — video games, reference works, social networking, etc. — can be enabled by downloading application programs (‘apps’).