The iPod Shuffle first and foremost is a flash based player. This means, that unlike the rest of the iPods that run on mini hard drives, the iPod Shuffle actually is solid state memory. No moving parts at all.

That is one of the reasons why it can be so small but does not hold as much.

Another big difference besides the size is that there is no screen. You can either shuffle all of your songs (120/240) or listen to them in order by Album.

Either way, the iPod Shuffle is darn neat.