Mainly, the bearings are used to allow rotation or linear movement on the purpose of reduces friction between two objects. There are two basic types of bearing which is Radial bearings and Thrust bearings.  Radial bearings is use to do rotating shaft bracket and the other bearings is support axial load.  Besides, ball and roller bearings are different on making contact with raceways. Ball bearing makes point contact with the ring raceways to increase the acting on the bearing. Then the contact point becomes an elliptical area. It enable ball bearing to accommodate high speeds but limited load- carrying capacity. Rollers make line contact with the ring raceways. It helps to increase the load acting on the bearing and the contact line become rectangular in shape. It can accommodate heavier loads but lower speeds.