All possible permutations of preferences in the 4 dichotomies above yield 16 different combinations, or personality types, representing which of the two poles in each of the four dichotomies dominates in a person, thus defining 16 different personality types. Each personality type can be assigned a 4 letter acronym of corresponding combination of preferences.
The first letter in the personality type acronym corresponds to the first letter of the preference of general attitude - “E” for extraversion and “I” for introversion.
The second letter in the personality type acronym corresponds to the preference within the sensing-intuition dimension: “S” stands for sensing and “N” stands for intuition.
The third letter in the personality type acronym corresponds to preference within the thinking-feeling pair: “T” stands for thinking and “F” stands for feeling.
The forth letter in the personality type acronym corresponds a person’s preference within the judging-perceiving pair: “J” for judging and “P” for perception.
ISTJ stands for Introverted, Sensing, Thinking, Judging
ENFP stands for Extraverted, iNtuitive, Feeling, Perceiving