What is a digipack?

When I first read the brief I was unsure of what a digipack was and what it included. I have done some research to ensure that I know exactly what needs to be included in my digipack for it to be successful.
A digipack is the packaging for a CD or DVD, this is the casing which typically consists of a book-style structure to open up the digipack containing a place for the CD, some use a sleeve which holds the CD whereas a more common way of securing the CD is the disc tray which is the 'teeth' of the hub.

4 Panel Digipack

 Sleeve Style Digipack