What is a Digipak/what needs to go on it?

Digipak is a patented style of CD,  DVD or BD packaging. Digipaks typically consist of a gatefold (book-style) paperboard or card stock outer binding, with one or more plastic trays capable of holding a CD or DVD attached to the inside. As part of our task we will need to produce a digipak so as we are going along we will be continuously thinking of ideas to go on the digipak.