EDIT - It has been pointed out to me below that I got this wrong. Chaotic, Neutral, lawful, Evil and Good are all seperate alignments. They do not cross over. I find this a little odd conceptually. Evil means likes doing harm and Neutral is described as "maybe the most self-serving of all". The whole thing strikes me a little queer but perhaps it would work in play.
Alignment interacts a lot with some classes, opening up certain paths and abilities and closing others. Evil characters may not become Bards.