It's a 'Briggs Myer' personality test that is popular here in the US (idk if it is also in other countries). But essentially there are four categories (Extraversion or Introversion, Sensing or iNtuition or , Feeling or Thinking, Judgment or Perception) and a total of 16 personality types. http://www.mbtionline.net.au/
ENFP, for example, is Extraverted iNtuitive Feeling Perceiving, "Extraverted Intuition with Introverted Feeling" http://www.personalitypage.com/ENFP.html
Overall it is pretty spot on, in my case. Anyways, you can try to find a free online version that is legit, but it is harder than I thought. :/ I remember taking it in a class years ago for the first time.
It's been said that your MB personality remains pretty consistent over your life.
Oh nooo your Donald <3