Blending brushes are makeup tools designed to seamlessly mix and diffuse products like foundation, blush, and eyeshadow. They typically have soft, fluffy bristles that help create a smooth, natural finish on the skin. These brushes come in various shapes and sizes, allowing for precise application in different areas of the face. Using a blending brush can enhance the overall look by softening harsh lines and ensuring even coverage. They are essential for achieving a professional makeup appearance, making them popular among both makeup enthusiasts and professionals in the beauty industry.