iPhone 4

Essentials
Family: iOS
Codename: ?
Minimum OS: iOS 4.0
Maximum OS: iOS 6.0
Introduced: June 2010
Processor
CPU: Apple A4 (ARM Cortex-A8)
CPU Speed: 800 MHz
FPU: integrated
Bus Speed: ?
Register Width: 32-bit
Data Bus Width: 64-bit
Address Bus Width: 32-bit
Onboard RAM: 512 MB
Maximum RAM: 512 MB
Level 1 Cache: 32 kB data, 32 kB instruction
Level 2 Cache: 512 kB on-processor
Video
Screen: 3.5" multi-touch
GPU: PowerVR SGX 535 (via A4 chip)
Max Resolution: 960x640 ("Retina")
Video Out: composite, component (via Dock Connector)
Camera: 5 MP back (w/LED flash), VGA front
Storage
Flash Drive: 16/32 GB
Input/Output
USB: via Dock Connector
Audio Out: stereo 16 bit mini
Speaker: mono
Microphone: mono
Sensors: Accelerometer, Proximity sensor, Ambient light sensor, Three-axis gyro
Networking
Airport Extreme: included
Bluetooth: 2.1+EDR
Cellular:
- GSM/EDGE (850, 900, 1800, 1900 MHz)
- UMTS/HSDPA (3.6 & 7.2 Mbps) (850, 900, 1900, 2100 MHz)
Location: GPS, Digital Compass
Miscellaneous
Battery Life:
- Talk 7 hrs (3G)/14 hrs (EDGE)
- Standby 300 hrs
- Internet 6 hrs (3G)/10 hrs (Wi-Fi)
- Video 10 hrs
- Audio 40 hrs
Dimensions: 4.5" H x 2.31" W x 0.37" D
Weight: 0.3 lbs.

Introduced in June 2010, the iPhone 4 replaced the iPhone 3GS, and included the same Apple-designed A4 processor found in the iPad. External improvements included a slimmer, redesigned case, a 5 megapixel camera with LED flash, a VGA-quality front-facing camera, and a stunning new 960x640 LED-backlit display. Apple claimed that the new display, branded the "Retina display," was so high-resolution that at at standard reading distances, the human eye would be unable to distinguish individual pixels.
Under-the-hood improvements included the afore-mentiond A4 processor, a faster graphics subsystem, improved battery life, and a 3-axis gyroscope which, when combined with the existing accelerometer, provided 6-axis motion detection. The iPhone 4 included the newly re-branded iOS 4.0, which brought a number of improvements, including multitasking and folders. In addition, the iPhone 4 included a new video calling feature, called "FaceTime," and the capability for 720p 30 fps HD video recording and editing.
The iPhone 4 was sold in two models, keeping the same price-points as the iPhone 3GS the year before: a black 16 GB model for $199, and white or black 32 GB models for $299, including a 2-year contract. Due to manufacturing and quality problems, the white iPhone did not ship until April of 2011. In October 2011 all models were replaced with a single 8 GB model (in white or black), for $99 with a 2-year contract (for AT&T or Sprint), or $549 without.
Picture Credits:
Apple, Inc.