The most well-known coordinate system is the Cartesian coordinate system. Cartesian coordinates (as part of Cartesian geometry) are determined by locating a point using the distances (measured in various units) from perpendicular axes. This system uniquely marks the position of a point on a plane by using two numbers (Cartesian coordinates), or in three-dimensional space by using three numbers—thus giving their distances from two or three mutually perpendicular lines (Cartesian axes).