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.
Copper Conductors
Annealed Bare Copper(ABC), Tinned PlatedCopper(TPC), Nickel Plated Copper(NPC), Silver PlatedCopper(SPC)
Thermocouple Conductors
Thermocouple grade conductor(TC)
Extension grade conductor(EX)
Compensating grade conductor (C)
Other Conductors
Pure Nickel Conductor (Ni) etc.