In RPG terms evil comes under the the definition of "guys who its ok to kill because they are not good"
Literally. You'll notice generally speaking there are few explorations of Orc culture, cause if you realized that that orc barbarian who is mapped on either a germanic raider or a viking raider is stealing food from a village for his starving kids (because his tribe has been ousted from the nice places to live by humans) it becomes a game that's vastly different from D&D.