Trauma refers to an emotional response that is much greater than the usual level of distress and discomfort for the presenting situation. It is almost certainly related to an event or events that have occurred in the individual's past.
Such an event or events may have caused sexual, physical and/or emotional trauma to the person who has been injured.
One of the most talked about types of trauma is Post Traumatic Stress Disorder or PTSD. And, although depression, anxiety and fears etc. so very often have their origin in past events, they cannot be considered in the same range as PTSD.
A useful way to view trauma is as a wound that has not healed. Once the healing is complete, however, the wound closes and becomes a scar. The facts have not changed, and the scar remains, but the hurt is no longer there to fester and damage.