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 effective for creating clean holes. These bits come in various sizes and materials, such as high-speed steel or carbide, to suit different applications. Twist drill bits are commonly used in both professional and DIY projects, making them essential tools in workshops and construction sites.