There are three main races, angels, demons, and humans. There are mixed breeds, but they are not to common with the war going on between good and evil.
Angels - Self explanatory as to their alignment (good). While the angels can keep a human appearance, they tend to take pride in their knowledge and can sometimes consider themselves higher than the other races. Most angels are mages, clerics, or warriors. Though there are angels who do not take these classes. Due to another part of their nature, angels can be very selfless when it comes to helping others. But Not all angels are like this.
Demons - Self explanatory here to. Evil. Demons aren't limited to having horns and wings, they can look human to. Demons most often times take the classes of assassin, necromancer, or warriors. Though they don't always choose one of those classes. Demons tend to think of only themselves, only taking others into consideration when it is in their favor or that other person is useful somehow. There are some demons who are more considerate, though not many.
Humans - They go either way. Some humans can be evil, some good, or neutral. There are even some demons and Angels that will join with the neutral humans. Humans can be any class they wish to be. The ones that use magic though are few compared to the human population. Those with magic are considered to be 'gifted'. Depending on the human's alignment though, this 'gift' is either from God or Satan.