rectangular coordinate system
- Also called Cartesian coordinate system. A coordinate system in which the locations of points are given in reference to the axes, numbering two or more. Each of these coordinate axes is perpendicular to the others, and all intersect at a common point called the origin. Each coordinate axis, or Cartesian axis, represents a plane called a Cartesian plane. A number of lines, equal to the number of planes, may be drawn from the origin to any given point on a plane or in space, and the exact location of this point can be specified by giving the coordinates with respect to the axes.