All the power and sophistication of the world’s most advanced operating system — OS X — is now available on a small, handheld device that gives you access to true desktop-class applications and software, including rich HTML email, full-featured web browsing, and applications such as widgets, Safari, calendar, text messaging, Notes, and Address Book. iPhone is fully multi-tasking, so you can read a web page while downloading your email in the background. This software completely redefines what you can do with a mobile phone.
Apple - iPhone
iPhone combines three products — a revolutionary mobile phone, a widescreen iPod with touch controls, and a breakthrough Internet communications device with desktop-class email, web browsing, maps, and searching — into one small and lightweight handheld device. iPhone also introduces an entirely new user interface based on a large multi-touch display and pioneering new software, letting you control everything with just your fingers. So it ushers in an era of software power and sophistication never before seen in a mobile device, completely redefining what you can do on a mobile phone.