The center component of any cable is the conductor which carries the signal or power through that cable. For signal & power transmission copper is the most commonly used conductor.
Annealed Bare Copper(ABC), Tinned PlatedCopper(TPC), Nickel Plated Copper(NPC), Silver PlatedCopper(SPC)
Thermocouple grade conductor(TC)
Extension grade conductor(EX)
Compensating grade conductor (C)
Pure Nickel Conductor (Ni) etc.