Question: what is the difference between single circuit and three circuit track lighting?
Answer: In a 1 phase rail (or 1 circuit rail) the electricity runs between just two wires, the phase (L for line) and the neutral wire (N). ... 3 phase rails have three phases (L1, L2, L3), which can be combined separately with the neutral wire (N). This creates the possibility to have three different circuits on your track.