The International Earth Rotation and Reference Systems Service (IERS) is an organization that monitors the Earth's rotation and provides precise data for global reference systems. It plays a crucial role in maintaining accurate timekeeping and positioning by tracking changes in the Earth's rotation and gravitational field. IERS produces essential products such as the International Celestial Reference Frame (ICRF) and the Universal Time (UT1), which are vital for navigation, astronomy, and geodesy. By coordinating with various global institutions, IERS ensures that scientists and researchers have access to reliable data for their work related to the Earth's dynamics.