Digipaks - what are they?

Seeing as I first studied the The Wombat's music video for Anti-D I thought I'd also look at their Digipaks. It was difficult to find actual images of their individual digipaks but I did find an image showing some of their albums and singles in almost every form.
I'm pretty sure the top row, minus the far left, are the digipaks... I like how they're consistent with their album artwork and from other images I've seen they've also been creative in the design on their disks as well.

I found this image of what one of their digipaks looks like once opened. I like they're use of 2 disks that are the same design but different colours (black on pink and pink on black) which still fit into a consistent house style. I think this digipak is practical and unique and fits the image of the band well. It expresses their fun and bold personalities as well as their music.