Coordinate system is a system for assigning an n-tuple of numbers or scalars to each point in an n-dimensional space. It anchors the regions within the real world. Coordinate system can have different types such as:

Rectangular cartesian
Cylindrical polar
Spherical polar
Prolate spheroidal
Oblate spheroidal

There is a global (world) coordinate system aligned with 3D rectangular cartesian space.

Coordinate system has the following attributes:

User number
Finished tag
Type
Number of dimensions
Focus (for prolate-spheriodal system only)
Origins
Orientation