Flaming refers to the use of hostile or offensive language in online communities or discussions, most commonly in the form of text-based messages. The propensity toward flaming is often attributed to the combination of anonymity and having an audience that is inherent in much online communication.
Flame wars occur when multiple users engage in flaming, either against one another or targeting a specific user or post. In either case, the result is a total breakdown of civil discourse.
Opinions are divided regarding the best way to resolve a flame war, but the two most common approaches are for administrators to message the instigators directly (assuming they can be identified) in an attempt to find a resolution, or to simply mute or ban them for further posting.