The story of Maleficent is the story of Sleeping Beauty wonderfully told from Maleficent's perspective. The story is told in third person through Maleficent with a splatting of Stephan's view point (you were learn about him from either of the two books based on the live action film or from the film itself.) The story tell the origins of Maleficent, how she grew up, why she placed a curse on Aurora and how her interactions with Aurora changed her destiny. Be warned, this is a darker version of the story based on the film and not really intended for young children. If you want to read the story of Maleficent to younger family members, check out, The Curse of Maleficent.
Maleficent is a fast paced read based more closely on the live action film Maleficent and being more heavily focus on Maleficent. It goes into more depth on the character of Maleficent and goes into more detail on her interactions with those around her (particularly with her raven) more so than The Curse of Maleficent.
All in all it is a great read!