Twist drill bits are cylindrical cutting tools used for drilling holes in various materials, including wood, metal, and plastic. They feature a helical design with two or more flutes that help remove debris while drilling. The pointed tip allows for precise entry into the material, making them versatile for different applications. These bits come in various sizes and materials, such as high-speed steel or carbide, to suit specific tasks. Commonly used in power drills and drill presses, twist drill bits are essential tools in both professional and DIY projects, providing efficiency and accuracy in hole-making.