The iPhone is a line of internet and multimedia enabled smartphones that are developed and produced by Apple Inch.The line was first introduced in January 2007 with the first generation of iPhones.The iPhone can perform simple mobile phone tasks,such as audio calls(and video calls for newer models),as well as more complicated ones.The phone also presents an internet and browser-based function that allows users to surf the web with the help of the implemented Wi-Fi technology.
The third function of the iPhone is that of a multimedia manager,which allows you to store your favorite music files and videos,and play them,as well as viewing your favorite pictures and photographs.The applications that the phone can execute are commonly known as Apps and they can only be obtained by visiting the official Apple online store (or the Apps Store) where are applications are verified and approved by Apple(unapproved software does not work on the iPhone).The diversity of these apps is huge as Apple statistics show their webstore currently holds over 20.000 applications from various domains such as games,social-networking,GPS systems like maps or a compass,and many others.
The iPhone has four distinct models:iPhone,iPhone 3G,iPhone 3GS and iPhone 4.The first iPhone came out in 2007 and the last one in 2010.Each model of this device holds key features like the 3G video call ability in the case of the iPhone 3G(from where it was named so in the first place).Although every model brought something new to the iPhone world,each has a set of features and characteristics that remain holly as they survived every wave of iPhones,such as the screen size,or the button alignment or positioning.
In order for one to use the iPhone's multimedia and internet features,he must first register the device as a mobile phone with a proper carrier,otherwise his access to those features remains restricted.However,a man called Jon Lech Johnson succeeded in July 2007 to bypass this requirement with the help of some simple software programs and some editing he did in the Apple iTunes binary code(which he later posted on his personal online blog so everybody could see how to unlock an iPhone.Later on came the iPhone 3G which was much harder to unlock than the original model,because it required an in-store activation.
It also presented a SIM Lock that prevented the phone from being used by more than one carrier,as only one particular carrier would be granted access(the carrier the user would register when he buys the device).In the end,hackers one again succeeded and managed to unlock the iPhone 3G as well,by registering it from other networks.The network that was granted permission to register iPhones is AT&T but only a quarter of the sold iPhones were actually registered to this company as unlocking the device seemed to be more popular for those who didn't afford to pay AT&T.Apple thinks that hackers shipped iPhones over the sea and had them unlocked there.
The situation reached a point where AT&T found itself obligated to sell the phones without contracts(although at a double price due to the differed income that both them and Apple Inc would lose).The other two versions that came after the 3G,iPhone 3GS and iPhone 4 were also unlocked.Modern unlocking is done by using a software named Jailbreak.