John G. Holland

John G. Holland was an American psychologist and philosopher known for developing the "Holland Codes," a personality-based career assessment system. These codes categorize people into six types—Realistic, Investigative, Artistic, Social, Enterprising, and Conventional—helping individuals identify careers that match their interests and strengths. His work aids in guiding career choices and understanding personality traits in a practical way, making career planning more personalized and aligned with one’s natural preferences.