A micrometer is a precision measuring instrument used to measure small distances or thicknesses with high accuracy. It typically consists of a calibrated screw and a scale, allowing users to measure objects down to one-thousandth of a millimeter. Micrometers are commonly used in mechanical engineering, manufacturing, and scientific research. There are different types of micrometers, including the outside micrometer for measuring external dimensions, the inside micrometer for internal dimensions, and the depth micrometer for measuring depths. These tools are essential for ensuring precise measurements in various applications, contributing to quality control and product specifications.