This information about geologic time and the geologic time scale defines the terms relative time (chronostratic) and absolute time (chronometric). Relative time can be thought of as the physical subdivisions of rock found in the Earth’s stratigraphy and absolute as the measurements taken upon those to determine the actual time that has expired. Absolute time measurements can be used to calibrate the relative time scale, producing an integrated geologic or geochronologic time scale. A feature of this site is the multicolor time scale and the site also contains references for more information.