What is a trigger?
A trigger is what sets you off. It can be completely unconscious, unless you have spent time trying to control your angry behaviour; then it can be something you become conscious of. It can be something that has you shouting in temper and acting very aggressively within moments.
Triggers can be anything at all really and what sets one person off may have no effect on another. Very often, our triggers exist because of previous bad experiences. For example, somebody who felt very vulnerable and shamed as a child after they did/said something may, as a grown up, experience an intense burst of anger if similar feelings arise.