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 hospital beds. Casters help reduce strain on the user by enabling smooth mobility across different surfaces. There are two main types of casters: swivel and rigid. Swivel casters can rotate 360 degrees, providing greater maneuverability, while rigid casters move in a straight line. Choosing the right type of caster depends on the intended use and the environment in which it will be used.