DISC is a framework for describing observable behavior: how you tend to make decisions, deal with people, respond to pace, and handle rules. It grew out of psychologist William Moulton Marston’s 1928 book Emotions of Normal People, and was turned into the self-report assessments used in workplaces today.
It sorts behavior into four styles: Dominance, Influence, Steadiness and Conscientiousness. Everyone uses all four. Most people lean toward one or two.
Know the limits. DISC describes preferred behavior, not intelligence, skill, values or fixed personality. It is popular for team communication and coaching, but it is not a validated clinical tool, and it should never be used for hiring or screening decisions.