A bearing is a mechanical component used to reduce friction and allow rotational or linear movement between two parts. It plays a crucial role in many machines and vehicles by supporting rotating shafts and other moving parts, enabling smooth and efficient motion. Bearings come in various types, including ball bearings, roller bearings, and thrust bearings, each designed for specific applications based on the nature of the load, speed, and environment in which they operate.

The primary function of a bearing is to facilitate smooth motion by providing a controlled and low-friction interface between two surfaces. In rotary applications, such as in motors, vehicles, or machinery, bearings allow the shaft to rotate freely while maintaining the alignment of the components. They reduce wear and tear, heat generation, and energy loss that would occur if metal parts directly rubbed against each other.