Have you ever heard someone describe themselves as an INTJ or an ESTP and wondered what those cryptic-sounding letters could mean? What these people are referring to is their personality type based on the Myers-Briggs Type Indicator (MBTI).

The Myers-Briggs Personality Type Indicator is a self-report inventory designed to identify a person’s personality type, strengths, and preferences. The questionnaire was developed by Isabel Myers and her mother Katherine Briggs based on their work with Carl Jung’s theory of personality types. Today, the MBTI inventory is one of the world’s most widely used psychological instruments.

Based on the answers to the questions on the inventory, people are identified as having one of 16 personality types. The goal of the MBTI is to allow respondents to further explore and understand their own personalities including their likes, dislikes, strengths, weaknesses, possible career preferences, and compatibility with other people.

No one personality type is “best” or “better” than another. It isn’t a tool designed to look for dysfunction or abnormality. Instead, its goal is simply to help you learn more about yourself. The questionnaire itself is made up of four different scales.