Digipak Vs. Jewel Cases.

Digipak:

 A digipak generally consists of 4 or 6 panels (+ spines). They contain either one of two CDs, or a mixture of CD and DVD (this is mostly for live CDs, such as The Black Parade Is Dead! - My Chemical Romance). They include all institution and band information, and most include a lyric booklet in a sleeve.

Digipaks are usually made of card and plastic, and usually have a promotional sticker on the front cover to aid sales.

Jewel Cases.

Jewel cases contain only four panels. They
generally contain one CD (with exceptions such as double albums (eg. Opposites by Biffy Clyro) or CD/DVD combinations, usually live albums. They are very basic, including only the CDs and very rarely lyric booklets. There is less space on a jewel case than a digipak, and so less design space. Jewel cases include all relevant institution information.

Jewel cases are usually made from clear, rigid plastics.

The main differences between the two are number of panels and production material. Because there are more panels and generally more extra material in a digipak, these are more expensive to make than a jewel case. Most music fans have also come to prefer the digipak, with complaints on the jewel case such as them cracking too easily or allowing the CD to fall out.
                                           

 Whilst digipaks are preferable to many music fans, they're actually more expensive to make. On oasiscd.com, a set of 300 digipaks would cost $890, which is around £565 in actual money. However, the same amount of jewel cases would cost $789, which is around £501. For this reason, digipaks are currently a bit more expensive to buy, but there is usually only a couple of pounds in it.