Idea is there are 16 personalities and you have one or are borderline for a few. There are 4 categories and 4 kinds of personalities for each category. Different events and experiences in your life affects your percentages (extroverted/introverted, intuitive/observant, thinking/feeling, judging/prospecting and then assertive/turbulent) The results are quite interesting and there are many studies, surveys, etc. diving into how this works. It's incredibly interesting I am a commander which is ENTJ-A/ENTJ-T but I used to be a debater which is ENTP-A/ENTP-T. Personally I am a ENTJ-A now but the change in percentages is interesting to see.
The website to learn more about this is called "the 16 personalities" where you can take a free test and make a free account if interested.
