Usually, Cartesian coordinates. a member of a system of coordinates for locating a point on a plane (Cartesian plane) by its distance from each of two intersecting lines, or in space by its distance from each of three planes intersecting at a point.
British Dictionary definitions for cartesian coordinates
Cartesian coordinates
plural noun
1.
a system of representing points in space in terms of their distance from a given origin measured along a set of mutually perpendicular axes. Written (x,y,z) with reference to three axes
mathematics, graphics (After Renee Descartes, French philosopher and mathematician) A pair of numbers, (x, y), defining the position of a point in a two-dimensional space by its perpendicular projection onto two axes which are at right angles to each other. x and y are also known as the abscissa and ordinate. The idea can be generalised to any number of independent axes. Compare polar coordinates. (1997-07-08)