Guitar strings are either made of nylon or stainless steel and both of these strings produce different sounds. Nylon is more likely a plastic string and does not rust, unlike stainless steel strings that will develop rust in the long run especially if you have clammy hands. Nylon strings are more gentle to the fingers than steel strings thus the choice of people who want to learn how to play this instrument.
Some acoustic guitars also have nickel-plated steel or pure nickel strings. The type of string has an effect on the sound the guitar is producing so some guitar players have their own preference depending on their music style.
Steel string acoustic guitar strings and electric guitar strings are made of metal. Modern classical guitar strings are made of nylon and nylon wound with wire, which produces a different sound to the metal strings. The invention of the electric guitar in the 20th century forced string makers to experiment with strings made of metals, such as bronze, nickel, and steel. There are three main types of guitar strings.
These are nylon for classical and folk guitars, bronze for acoustic guitars, and steel/nickel used for electric guitars. Until the early 1900's, all guitar strings were made of animal gut, and were referred to as "gut strings."