1st gen iPod
Released: October 2001
Details: 5GB, FireWire, battery: 10 hours audio
A 10GB version was released later. This model contained a mechanical scroll wheel that physically turned when you moved it with your finger.
2nd gen iPod
Released: July 2002
Details: 10, 20GB, FireWire, battery: 10 hours audio
The first Windows compatible iPod also saw the introduction of the first touch sensitive scroll wheel to the iPod. Original Windows support was via Musicmatch.
3rd gen iPod
Released: April 2003
Details: 10, 15, 20, 30, 40GB, FireWire (USB for syncing only), battery: 8 hours audio
The first all-touch sensitive interface was part of a complete redesign of the entire device. At the same time, iTunes becomes available for Windows.
1st gen iPod mini
Released: January 2004
Details: 4GB, FireWire, USB, battery: 8 hours
A new smaller iPod that was available in five colours, and the introduction of the first Click Wheel, which contained the buttons themselves.
4th gen iPod
Released: July 2004
Details: 20, 40GB, FireWire or USB, battery: 12 hours audio
The first full iPod to use the new Click Wheel from the iPod mini. The Click Wheel has been a staple ever since.
4th gen iPod photo
Released: October 2004
Details: 30, 40, 60GB, FireWire or USB, battery: 15 hours audio, 5 hours slideshow
This was the first ever iPod with a colour screen. It could display photos synced from your Mac or PC.