A Coordinate System is a system which uses a set of numbers, called coordinates, to determine the position of a point.
Common Coordinate Systems
Cartesian Coordinates: In two dimensions, specify the position of a point by two numbers, which represent the distance of the point to two perpendicular lines, called the axes. The distance may be positive or negative. This system may be generalized to any higher number of dimensions.
Plane polar coordinates: Specify the position of a point with a pair of numbers, one representing the distance to a fixed point, called the origin, and the other representing the angle with respect to a fixed direction.
Spherical Coordinates: Specify the location on a sphere. This may also be referred to as Spherical Polar Coordinates.