Lapping is a machining process used to achieve a high degree of surface finish and precision. It involves the use of a rotating lap, which is a tool made of a soft material, often embedded with abrasive particles. The workpiece is held against the lap, and the combination of the lap's motion and the abrasives helps to smooth and polish the surface. This technique is commonly used in industries such as automotive and aerospace, where components like engine parts and optical lenses require exact dimensions and a fine finish. Lapping can improve the flatness and surface quality of materials, making it essential for high-performance applications.