Casters are small wheels or rollers attached to the bottom of furniture or equipment, allowing for easy movement. They come in various sizes and materials, such as plastic, rubber, or metal, and can be found on items like chairs, carts, and cabinets. Casters can swivel for better maneuverability or be fixed in one direction for stability. There are different types of casters, including swivel casters, which rotate 360 degrees, and rigid casters, which move in a straight line. Some casters also have brakes to prevent movement when needed. They are commonly used in homes, offices, and industrial settings for convenience and efficiency.