The main difference between a roller bearings and a ball bearing is in the contact areas of the rolling elements. Rollers have linear contact while balls have point contact. Roller bearings therefore have higher radial load carrying capacities, but usually operate at lower speeds due to greater friction caused by a larger contact area. This makes roller bearings more suitable for use in heavy assemblies. Roller bearings can have either cylindrical or tapered rollers – each having unique benefits over the other and are chosen depending upon application requirements.