I think trauma is any external event that negatively impacts or interrupts the normal course of human development. So it can be physical (e.g. a broken bone) or psychological (emotional abuse). It can be a one off event (a car accident) or ongoing (bullying). It can be healed (emotional nurturing protection and restoration after abuse) or it can b permanent (head injury). It can be simple (a physical injury as a a result of an accident) or it can be catastrophic (severe ongoing abuse from early childhood that impacts every area of the individuals psycho social development).