Trauma can be beating, hitting, neglect, abandonment, verbal abuse, putting down, not making the child feel loved and cared for, sexual abuse (rape, fondling, forcing the child to perform sex, talking to child about sex in an inappropriate way, having child watch sex), exposing child to violence or situations that scare them (purposely), threatening to harm or abandon, and more depending on the situation.....

Really anything that is not good for the child emotionally. What harms one may not harm another, but some things you should never do to a child.