Cartesian coordinates
rectangular coordinates

In one form of mapping, the galaxy is mapped using 3-dimensional Cartesian Coordinates to enumerate the sectors, centered on earth.

Most of the fluid flow equations are easily solved by discretizing procedures using the Cartesian Coordinates system.)

Then the Toroidal/Poloidal coordinate system relates to standard Cartesian Coordinates by these transformation rules:

The Geometry Center: 10.1 Formulas for Symmetries in Cartesian Coordinates (three dimensions)