There are at least six common principles of operation of bearings:
- plain bearing, also known by the specific styles: bushings, journal bearings, sleeve bearings, rifle bearings.
- rolling-element bearings such as ball bearings and roller bearings.
- jewel bearings, here the load is carried by rolling the axle slightly off-center.
- fluid bearings, here the load is carried by a gas or liquid.
- magnetic bearings, here the load is carried by a magnetic field.
- flexure bearings, here the motion is supported by a load element which bends.