NAVD88, or the North American Vertical Datum of 1988, is a standard used in the United States and Canada for measuring elevation. It provides a consistent reference point for determining the height of geographical features, such as mountains and valleys, as well as for various engineering and construction projects. The NAVD88 system is based on a network of survey benchmarks and uses precise measurements to establish a baseline for elevation. This datum replaced the earlier NGVD29 (National Geodetic Vertical Datum of 1929) to improve accuracy and reliability in height measurements across North America.