datum system

A datum system in geodesy is a reference framework used to define the position of points on Earth's surface. It provides a consistent coordinate system, including an origin point, orientation, and scale, so that measurements like maps and GPS can align accurately. Essentially, it's like a virtual grid that helps us describe locations precisely, based on a chosen reference point and orientation. Different datums exist because Earth isn’t a perfect shape, and selecting one affects how measurements relate to actual positions on the ground.