What Is a Swivelling Wheel Called?

A caster (or castor) is an undriven wheel that is designed to be attached to the bottom of a larger object (the "vehicle") to enable that object to be moved.

What are wheels on furniture called?

Furniture casters are wheels that attach to the leg of a piece of furniture, allowing it to roll.

What is the difference between a wheel and a caster?

The wheel is limited in that it only spins on a single axis. It can only roll in one direction at a time. Casters incorporate wheels into their designs, but they are a bit more sophisticated. A caster includes the mounting system that holds the wheel in place.