What is a Digipak?

Here I thought I'd research what a Digipak really is and how they are formed. This is what i found on the internet.

'Digipak is a patented style of CD, DVD or BD packaging, and is a registered trademark of AGI-Shorewood, an Atlas Holdings LLC company.'

Its features 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.

Here are some examples of artists digipak designs-