A swivel caster consists of three key components. Firstly, there's the top plate, a rectangular piece with four holes that securely attach the caster to the equipment—secondly, the wheel, which makes direct contact with the floor and enables smooth rolling. The axle and ball bearings form the third part, with the axle connecting the wheel to the caster assembly and the ball bearings allowing the caster to rotate effortlessly in any direction. These components facilitate easy movement and direction changes for swivel casters, commonly found in shopping carts, chairs, beds, and handling equipment.