The info I currently have below will be very helpful for many people. This is why I put it up before finishing it.
Aggression is when a dog growls, bites and snarls with or without hackles up and wide eyes.
The fear level is low. This doesn't hold true for a dog trained to bark on command. Growling means the dog is insecure of the situation. There is moderate to high fear level. Snarling is when the dog is growling with a nose sound added to it.