The iPhone can function as a mobile phone,used for texting and calling(both audio and video for some newer models),a multimedia manager that allows you to store,organize and play your favorite tunes,watch your favorite movies,or view your favorite photos,or an Internet and browser-based device that you can use for surfing the Internet with the help of the implemented Wi-Fi technology.
The device can execute a large number of applications (commonly known as apps,a term quite familiar for those who often use Apple products).These applications must be first checked and approved by Apple in order for them to function on the device,and the only way to obtain them is by visiting the official Apple online store,often called AppStore. There are currently over 20.000 apps registered on the official AppStore, integrated in several domains,such as gaming,social-networking,GPS and maps,multimedia,internet,and some familiar names as well,like YouTube,Twitter,FaceBook,and others.
There are currently four models of iPhones available,the first one having been launched in 2007 and the last one in 2010.Each model brings some improvements and upgrades but they all share some characteristics and details that are iconic for the iPhone, like the size of the screen,or the button positioning.The iPhone is also known for its lack of physical button,as only two buttons of that kind are available to all models (except for newer revisions which have side volume keys,as these were originally implemented in the multi-touch display.The only physical buttons on the device are the Home button,used for redirecting one to the home screen,and the Awake/Sleep button which,as it suggests,turns the iPhone on or off.
In order for one to gain access to the iPhone's internet and multimedia features,he must first register the device as a mobile phone that holds a proper carrier.This practice is often used at GSM subsidized phones,but opposing them,iPhones cannot be activated by introducing a code of any kind. However,a man named Jon Lech Johnson succeeded a few months after the release of the iPhone to bypass this requirement with the help of some software programs and by editing some data in the iTunes binary.When the iPhone 3G(second model)came out,things seemed a bit tricky,as Apple implemented an in-store activation which made it harder for hackers to unlock the device.
This wasn't impossible,as hackers succeeded in unlocking the device by registering it to different networks.The original network intended for iPhones as Apple agreed,was AT&T but only a quarter of the total number of sold iPhones was actually registered to this network.Apple speculates that hackers shipped the iPhones over the sea and had them unlocked there.AT&T even started to sell iPhones without contracts,but at a double price so they wouldn't lose the differed income.