A geodetic reference is a framework used to define the size and shape of the Earth, as well as the position of points on its surface. This framework helps in accurately measuring distances and angles for mapping and navigation. It is essential for various applications, including GPS technology, land surveying, and cartography. Geodetic references are based on mathematical models, such as the WGS84 (World Geodetic System 1984), which provides a standard for global positioning. These models take into account the Earth's irregular shape and gravitational variations, ensuring precise location data for users across different regions.