According to the Myers & Briggs Foundation

Quote:
The purpose of the Myers-Briggs Type Indicator® (MBTI) personality inventory is to make the theory of psychological types described by C. G. Jung understandable and useful in people's lives. The essence of the theory is that much seemingly random variation in the behavior is actually quite orderly and consistent, being due to basic differences in the ways individuals prefer to use their perception and judgment.

Each personality consists of four pairs of preferences as follows:
I - Introverted, E - Extroverted
S - Sensing, N - Intuitive
T - Thinking, F - Feeling
J - Judging, P - Perceiving

The Myers-Briggs personality test consists of about 70 yes and no questions. If you answer honestly and truthfully the results can be incredibly accurate

Here is a link to the Myers-Briggs personality test

I personally think it is a good way to better understand someone else's way of thinking/actions by knowing her/his personality type

EDIT:

Here are the 16 possible combinations along with their Keirsey Temperament Sorter:

ISTJ Inspector
Ed Hunter, Opium, GT, +{Jonas}+, Sunioj, Oyvind

ISFJ Protector
Ernotar, FourSuits

INFJ Counselor
duyhung

INTJ Mastermind
Bararey, Deus Ex Machina, cursed, Torelli, BloodTears, Baerd, Insineratehymn, Asphyxia, selken

ISTP Crafter
tulkas

ISFP Composer

INFP Healer
Nervel

INTP Architect
Keoren

ESTP Promoter
Damnated

ESFP Performer

ENFP Champion

ENTP Inventor
Elijah

ESTJ Supervisor
Warman

ESFJ Provider
Vrana of steel

ENFJ Teacher
Wulfthryth

ENTJ Field Marshal
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