A gravimeter is an instrument used to measure the strength of gravitational forces at a specific location. It detects tiny variations in gravity caused by changes in the Earth's density, such as underground structures, mineral deposits, or geological formations. This information is valuable in fields like geology, archaeology, and environmental studies. Gravimeters can be classified into two main types: absolute gravimeters, which measure the gravitational acceleration directly, and relative gravimeters, which measure changes in gravity relative to a reference point. These devices help scientists and researchers understand Earth's structure and dynamics more effectively.