In mechanical engineering, bearings are crucial components that support the rotation or linear movement of machinery parts. They reduce friction between moving parts and help in transmitting loads smoothly. Bearings come in various types such as ball bearings, roller bearings, and plain bearings, each serving specific purposes based on the application requirements. Proper selection and maintenance of bearings are essential for ensuring the efficiency and longevity of machinery and equipment. Engineers need to consider factors like load capacity, speed, lubrication, and environmental conditions when choosing the right bearing for a particular application.