There are many different kind of bearings: Plain Bearing, Rolling Element Bearing, Fluid Bearing, Jewel Bearing, Magnetic Bearing and Flexure Bearing. Each of them has their own life span, usage, friction, stiffness and speed. It is important to choose the right bearing for the right usage. Apart from that, bearings also need to have maintenance from time to time to make sure its condition is good and safe for using it continuously.