The RIASEC hexagon is a visual model of John Holland's theory that categorizes people into six personality and interest types: Realistic, Investigative, Artistic, Social, Enterprising, and Conventional. These types are arranged in a hexagonal shape to show how similar interests are located next to each other, while opposite types are at the farthest points, helping to match people with suitable careers and work environments. 

The six RIASEC types:

• Realistic (R): "Doers" who prefer hands-on, mechanical, or athletic activities.

• Investigative (I): "Thinkers" who enjoy observing, learning, analyzing, and solving problems.

• Artistic (A): "Creators" who are drawn to self-expression through performing, visual, or written arts.

• Social (S): "Helpers" who prefer working with people to help, inform, or train them.

• Enterprising (E): "Persuaders" who like to sell, manage, and influence others, often in a business context.

• Conventional (C): "Organizers" who prefer structured tasks and systematic work with data and details. 

How the hexagon is used:

• Career planning: The model is used to help individuals identify their strongest interests and find careers that align with them.

• Visualizing relationships: The hexagon shows that interests are on a continuum; for example, Investigative and Artistic are closer to each other than to Realistic.

• Finding a match: A person's profile is a unique combination of these types. The model helps in finding jobs or majors that match this combination, leading to a better fit between person and environment.

• Assessment tool: Various assessments use the RIASEC model to provide a letter code that describes an individual's career interests. The U.S. Department of Labor's O*NET system uses this framework to categorize occupations and help users match their interests to relevant career paths.