The iPhone can function as a camera phone which also has text messaging and visual voice mail,a media player,designed for playing your favorite audio tracks or movies,as well as viewing your favorite photos,or an internet client that has e-mail,web browsing and Wi-Fi connectivity.
The user interface of the device is built around its multi touch screen.Apple decided to implement a virtual keyboard instead of a physical one.The multi touch sensitive screen allows user not only to use their bare finger on the display,but also use several finers at once,for functions that require it,such as zooming in or out of a web page.Third party applications for the iPhone are available only through the AppStore.The AppStore was launched in 2008 and since then Apple managed to store over 300.000 applications on the webstore.If one uses third party applications that were not approved by Apple and obtained via AppStore,the device could suffer serious software malfunctions that won't be covered by the iPhone's warranty.
There are currently four generations of the iPhone available,each of them being released alongside a major version of the iOS.The iOS was first called the iPhone OS and it is an operating system intended for Apple products and was developed by Apple itself.The iOS is now the operating system of all major Apple products(which share the multi touch screen),like the four generations of the iPhone,the iPod Touch and iPod Touch 2.0 media player,and the iPad tablet computer.The first iPhone model was launched in 2007,and even tough it got old,it features some characteristics that have become iconic for all iPhones,as they persisted through all four generations,like screen size or button placement.The iPhone has only two physical buttons,as the other are part of the virtual display.The first physical button is the Home button,which is called so because by pressing it,users are redirected to the home screen of the iPhone.
The other button is the Awake/Sleep button and is located on top of the device.It basically turns the phone on and off,but can also perform other tasks,like changing the phone's mode to silent when reciiving a call.The second iPhone generation,the iPhone 3G introduced 3G cellular network capabilities and A-GPS location.The third generation called iPhone 3GS introduced a compass,better processing technology and a higher resolution camera that also included video capabilities.The iPhone 4 has two cameras for FaceTime calling and a higher resolution screen. A CMDA version of the iPhone 4 is set to be released in the first quarter of 2011 which would be compatible with the Verizon Wireless network.The original iPhone 4 model was launched on June 24,2010 and represented the fourth generation of the iPhone family.