A "caster" is a small wheel or set of wheels that is attached to the bottom of furniture or equipment, allowing it to move easily. Casters are commonly found on items like office chairs, carts, and hospital beds, making them more mobile and convenient to use. They can be fixed or swivel, providing different levels of maneuverability. Casters come in various sizes and materials, such as rubber or plastic, to suit different surfaces and weight capacities. They are often used in commercial and residential settings, enhancing the functionality of items like furniture and industrial equipment.