A foundation brush is a makeup tool designed to apply liquid, cream, or powder foundation evenly on the skin. It typically features a flat, dense bristle head that helps achieve a smooth and flawless finish. Using a foundation brush can provide better coverage compared to applying foundation with fingers or sponges. These brushes come in various shapes and sizes, allowing for different application techniques. Some popular types include the flat foundation brush, buffing brush, and angled foundation brush. Choosing the right foundation brush can enhance the overall makeup look and ensure a more professional appearance.