The 2007 iPod release, the sixth-generation iPod classic, is a digital audio player, video player, photo viewer and portable hard drive, making it a full-fledged portable media center. It's available in 80-GB and 160-GB capacities and has a color LCD screen. In addition to the iPod classic, there are several other devices in the current generation of iPod players:
iPod touch, announced in September 2007, is a touch-screen iPod with an 8-GB or 16-GB capacity. It looks a lot like an iPhone, and it uses the iPhone's multi-touch user interface. You can learn all about the technology in How the iPhone Works.
iPod shuffle, with a 1-GB capacity, plays only songs and has no display. iPod nano plays digital audio, displays digital photos and comes in 4- and 8-GB capacities. It has a 2-inch display screen and a smaller form factor than the iPod video.