Screen size: 3.5 in
-Screen resolution: 480×320 px at 163 ppi, with 3:2 aspect ratio
-Input method: Multi-touch screen interface, Sleep/Wake button, Accelerometer, Home button, Volume Rocker buttons (2nd/3rd Gen only)
-Operating system: iPhone OS (current version 3.1)
-Storage: 8 GB for 2nd Gen or 32 and 64 GB for 3rd Gen flash memory
-CPU: Initially ARM 400 MHz, but now 412 MHz for 1st generation, 533 MHz [28] for 2nd Generation and ARM Cortex-A8 833 MHz for 3rd Generation
-GPU: PowerVR MBX Lite in 2nd Generation [30] and PowerVR SGX GPU for 3rd Generation
-RAM: 128 MB DRAM in 2nd Generation and 256 MB DRAM in 3rd Generation
-Wi-Fi (802.11 b/g)
-uilt-in rechargeable, non-removable lithium battery with up to 6 hours of video playback, and up to 36
-Built-in audio speaker
-3.5 mm audio output jack