The iPhone is a multimedia and Internet enabled smart phone released and designed by Apple Inc. It has some specific functions as a PMP, which is equivalent with the iPods, a video camera which it is perfect for multimedia messages or visual voice mails, an internet client with web browsing, wi -fi and e- mail functions. This comes in a well- designed case, with a multi- touch display which can render a virtual keyboard in QWERTY system.
The 1st generation of iPhones, also known as Original, had enhanced data rates for GSM evolution, a digital mobile phone technology that will allow the improved data transmission rates, as an annex to the top of classic GSM. This technology it is also named, in its short form, as EDGE. With the second generation of iPhones, Apple Inc. added to this smartphone an universal mobile telecommunications system, UMTS, as a part of the International Telecommunication Union, being a totally and complete network system. This technology will allow users to listen radio, authenticate via USIM cards ore use a web network on a 3,6 MB per second band width. Beside this feature, the 3G model of iPhone incorporates also a high speed downlink packet access which allows the network to have a high data transfer capacity and speed with 7,2 MB per second, but limited to 384 kb per second upload.
This smart phone was released after couple of months of rumors, in January 9, 2007 and first was introduced in U.S.A, and after its real success in 22 countries of Europe and Asia. On March 17, 2009, was announced a new version of the iPhone OS, the operating system used on this model, and released at the middle of 2009.
At the hardware part, iPhone 3G is almost perfect for anybody. Its case is made completely  from a hard plastic material, despite the Original which have some aluminum parts. The touchscreen has 9 cm dimensions and it is made from liquid crystals with 320 x 480 pixels and 160 ppi. The display contains also a scratch resistant glass and can render exactly 262 144 colors. For a multi touch sensing, the screen is projected for a bare hand or a touch with multiple fingers. A fingerprint resistant coat it is also included in the features of this display. Three sensors are integrated so that the battery to be properly saved and the user more comfortable when he is watching videos or photos.
The 3G iPhone is available with a full plastic back, for an increased in strength of the 3G signal. Â The 8 GB model is available in black color and the 16 GBÂ either in white or in black. The 3GS iPhone is available in both colors.
Even if the Original model had a headphone socket incorporated which had a sunken area into the case, which made it compatible only with the Apple headphones, at the 3G model this problem was solved by adding a flush mounted headphone socket.
The 3G model is capable to storage up to 32 GB, but can be found also in 8 GB and 16 GB capacity varieties. The processor it is made by Samsung and have an ARM7 core for Jazzele acceleration. The flash memory it is 128 MB of DRAM. For connectivity it uses Bluetooth 2.1+ EDR , have a built in speaker and hardware volume controls. It also have the Nike+  Kit that measures the foot steps and record them.
For power it has a built in rechargeable Li-On polymer battery rated for 36 hours of continuous music or 6 hours of video replaying.
The dimensions are pretty small, the iPhone 3G measuring only 110 x 61.8 x 8.5 millimeters to a weight of 115 grams.
To prevent the hack or the third party applications, also called  jail breaking, the iPhone’s operating system is designed to launch and run only software that have a cryptographic signature approved by Apple. Also the phone prevent access to media player and web since it is activated as an Apple device to an authorized carrier. Despise this facts, there are a lot of programs cracked for this phone and a lot of methods to unlock it, by replacing the   Firm Ware software with a modified version that don’t need the signature check.