A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. ... However, they can tolerate some misalignment of the inner and outer races.

Ball bearings are simple and the most versatile rolling bearings used in a wide variety of applications. Ball bearings are classified into radial and thrust ball bearings based on their primary load carrying direction.