C
Cbelectrics
in domestics, we generally use twin& earth cable. :
View attachment 51089
hot wire we call line(brown) . neutral (Blue), and what you would call the ground wire, we call it "circuit protective conductor (cpc). OH, and due to some silly farts back in the 1970's all our cable is metric.
that's a start
Actually a good thing that was introduced. Was to avoid massive blunders happening in the scientific community where conversions would be made from old imperial measurements to metric. Everything from engineering/satellite's/chemistry (all relatable to electrics).