The color wheel is a visual representation of colors arranged according to their chromatic relationships. It is used in various fields such as art, design, and color theory. Understanding the color wheel involves recognizing primary colors (red, blue, yellow), secondary colors (green, orange, purple), and tertiary colors (mix of primary and secondary colors). It also includes concepts like complementary colors, analogous colors, and triads. This knowledge helps in creating harmonious color combinations and understanding color interactions.