Rigging holds up spars. Rigging consists of forestays, backstays, shrouds. The rigging material can be either wire or rod.
Wire
Wire rigging is the traditional type. Most cruising boats have wire. Wire has two benefits: replacing and maintaining.
For replacing, any where you go likely some one has wire. If you have a problem in a third world port, likely some one there will have the expertise and materials to replace your stay or shroud. Wire is the historical standard everywhere. For maintaining, wire is easier to examine. You can see cracks and brittleness. The wire is simple, out in the open. By looking you can watch and maintain the wire before a serious problem occurs. You can see individual strands break one by one. Wire rigging typically lasts 10 years. The price for wire rigging on a 40 foot cruiser should be around $5,000. But if any rigger tells you categorically to replace rigging after 10 years he/she is trying to make money off you. It all depends on use and location. Ten years of bareboat charters is the Caribbean is wholly different than the wear and tear of summer use on the Greak Lakes.
Rod
Rod rigging gives high performance. Instead of the standard stainless steel wires, you stay the mast with specially alloyed metal rods, Nitronic 50. Rod rigging is rare on cruisers and strangely loose compared to standard wire. It may puzzle you. You can shake the stays, and they reverberate up to the mast tip and down. Because of the stiffness of rods, the mast sets just as a racing boat wants. The rigging does not stretch. The mast stays vertical catching the wind perfectly. Rod rigging is high performant grabbing more wind and shooting the boat past any similar sized standard stayed boat. Rod rigging is universal on racing boats. Rod rigging also generally last longer than wire, 20 years. Cost for a 40 foot racer would be four times the cost of wire, $20,000.
Conclusion
Rigging can be one of two types: wire or rod. Wire is usual for cruisers. Wire is easier to replace and maintain. Rod is for racing boats. Rod rigging stiffens the mast catching more efficiently the wind. For cruisers, rod lasts longer. In comparison, rod is 4 times more expensive. Usually, price is the determining factor.