The iPhone can be used with three distinc purposes,as you can call it a mobile phone,used for texting and calling(audio and video calls)which is also the main purpose of the device,a multimedia manager,used for storing and playing music files or videos,as well as viewing your favorite photos,or you can use it as an internet and browser-based device,as the iPhone has implemented modern Wi-Fi connection technology.
The iPhone executes a huge variety of applications that are also known as iPhone Apps,Apple iPhone Apps,or just Apps.These apps have to be aproved by Apple Inc. itself in order for the device to recognize them.The only way you can get in touch with these apps are by visiting the Apple official online store where the company has registered over 20.000 applications from various domains such as gaming,social-networking,GPS systems like a compass,maps an others,and the list can continue.
The iPhone currently comes in four different models,as the last iPhone generation came out in 2010.Altough every iPhone model has some distinct an new features that represent them one way or another(like the 3G video call feature in the case of the iPhone 3G),every iPhone has a set of features charcteristic to all devices that survived from the original phone,such as the size of the screen,the button alignment and positioning,and others.
Since the original version,iPhones require the client to register it as a mobile phone first,if they want to use the internet or multimedia features,otherwise these restrict acces.A proper carrier is also needed.On July 3,2007 however,a man called Jon Lech Johnson discovered a way to bypass this requirement and use the other features as well.He did so with the help of some software programs and editing specific data in the iTunes binary.
Later he posted the needed information on his personal blog so anyone could unlock their phones.Later on came the second version of the iPhone named iPhone 3G due to its characteristic 3G video call feature.This model was tougher to unlock because opposing the first generation,this one asked for in-store activation.The iPhone was sold with a SIM Lock that resticted acces to the device for a single carrier which would be registered when buying the phone.Hackers took their time and in the end discovered a way to unlock this phone as well.
They managed to register the phones from other networks.Originally,the iPhones were registered to AT&T for U.S. territory but only a quarter of the total number of iPhones were actually registered to that company.Apple thinks that people shipped large numbers of iPhones over the sea and had them unlocked there.The next two versions of the iPhone,named iPhone 3GS and iPhone 4 were also unlocked.