The iPhone is an integrated cellular phone which is designed, developed and marketed by Apple Inc. An iPhone is an Internet and multimedia-enabled Smartphone. The iPhone runs on a special version of Apple’s Mac OS-X operating system. Many application software is available for iPhone. An iPhone has much feature and functionality like mobile phone , portable media player, video camera, games, can send and receive visual voicemail, wireless Internet device, iPod, an Internet client with email, web browsing GPS navigation and social networking capabilities with both Wi-Fi and 3G connectivity. The original iPhone was a GSM phone that established design precedents like screen size and button placement that have persisted through all models.