Cores / Conductors: The core count is typically the number of internal wires, and these, in turn, contain the conductors, which are normally solid or stranded.

Which Cable or Flex? - 218x or 219x: upto 3A; otherwise 318x or 319x for upto 6A.

VAC: Volts Alternating Current
VDC: Volts Direct Current

Harmonised? - In the wire, cable, and flex descriptions harmonised means that the conductors have been coloured according to a recognised standard. In household electrical cable this is commonly seen in the form of blue for neutral, brown for live, and green/yellow for earth; the use of red for live, black for neutral and green/yellow for earth is no longer used.