Any system used to mathematically indicate location. Most coordinate systems utilize two axes (a horizontal, called an x-axis, and a vertical, called a y-axis), coordinates being plotted with respect to variables indicated along both axes. Such a system is known as two-dimensional, as only two variables are mapped; an additional z-axis is often added to add a third dimension. A graph is a basic coordinate system, often using only two axes. Graphics and page layout programs allow objects to be drawn or positioned by means of coordinates.

In three-dimensional modeling, different sets of coordinates are used: world coordinates are absolute, fixed coordinates, while modeling coordinates and eye coordinates are coordinates defined in terms of a particular viewing angle.