As far as I have used the Emotion Code and seen the effects on releasing trapped emotions, I would say that they are both those negative emotions that we do remember and don't remember. Sometimes an emotion becomes trapped in us when we were very young, e.g. <1 year old, but it is still in us. It would be almost impossible (as far as my experience) to release it with EFT only. Luckily, it can be released with the EC.
Also, we inherit some emotions from our parents or grandparents! With the EC we can release them as well

Hope I was able to clarity this point.
Peace