What type of coordinate system is used in a Smith chart?

The Smith chart plots complex impedance using a unique non-Euclidean coordinate system. This system is made entirely of constant resistance circles and constant reactance arcs. The circles that are tangent to the extreme right side of the chart represent purely resistive values. The sweeping arcs that originate from the right side and curve upward (inductive) or downward (capacitive) represent reactive values. Distractors mentioning voltage or current lines are incorrect because the chart plots impedance components (R + jX).