Surface error refers to the deviation between the desired or ideal surface shape of an object or material, and the actual or measured surface shape. This research area focuses on studying and quantifying the various types of errors that can occur on a surface, such as roughness, waviness, form errors, and scratches. Researchers in this field work to develop methods and technologies to accurately measure and analyze surface errors, as well as to improve manufacturing processes to minimize these errors. Surface error research is important in a wide range of industries, including aerospace, automotive, electronics, and medical devices, where precise surface quality is critical for performance and reliability.