i Pod nano is smaller than i Pod mini and has a color screen and a Click Wheel but has flash memory instead of a hard drive.
You sync music and photos with a USB 2 cable—not Fire Wire.
i Pod (Click Wheel) models have a Click Wheel like the i Pod mini, but are larger and the hold switch is on the top-right side.
i Pod (Click Wheel) models have a monochrome display.
In June 2005, a new version of the i Pod Special Edition U2 was introduced that was based on an i Pod with color display.
These are both also considered fourth-generation i Pod models.
You can distinguish the i Pod touch (2nd generation) from the previous model by its contoured design and oval shaped antennae cover in the back upper left corner.
i Pod touch features a 3.5-inch (diagonal) widescreen Multi-Touch display and 8 GB, 16 GB, or 32 GB flash drive.
In June 2006, a new version of the i Pod Special Edition U2 was introduced that is based on a 5th-generation i Pod (also known as i Pod with video) with a 30 GB hard drive.
In September 2006, a model based on the i Pod (5th generation Late 2006) was introduced.
They continue to have the same controls as i Pod (Click Wheel) but now all models have a color display like i Pod photo—ideal for viewing album artwork and playing slideshows.