What each winding alloy is, and which sets you can listen to in each group.
Phosphor bronze: Phosphor bronze is a copper alloy, roughly 92% copper and 8% tin with a small amount of phosphorus, wound around a steel core. It is the most common winding alloy for acoustic guitar strings today.
80/20 bronze: 80/20 bronze is 80% copper and 20% zinc (metallurgically a brass). It is the original acoustic winding alloy, still offered by every major brand.
85/15 bronze: 85/15 bronze is 85% copper and 15% zinc, an intermediate formula between 80/20 bronze and phosphor bronze.
Nickel and Monel: Nickel-based windings: pure nickel wrap wire, and Monel, a nickel-copper alloy (about two thirds nickel) used on acoustic strings since the 1930s.
Coated strings: Coated strings carry a thin polymer layer, or a surface treatment, over the wrap wire to slow down corrosion and dirt build-up. Each maker uses its own process.