Coordinate systems.

Coordinate systems are frameworks that provide a way to define the position of points in space. They use numbers to specify locations; for example, a 2D Cartesian coordinate system uses two numbers (x, y) to mark a point on a grid. In 3D, a third number (z) is added for depth. Other systems, like polar coordinates, use angles and distances from a central point. Coordinate systems are essential in fields like geography, physics, and computer graphics, as they help in mapping, navigation, and modeling spaces accurately.