Generally speaking there are two types of guitar strings that are made.
Steel used on electric and acoustic guitars
Nylon primarily used on classical and flamenco guitars
Guitar strings are normally wound with either type of nickel, brass, or copper alloy. On most standard set of strings for an electric guitar, the 1st – 3rd string is usually unwound, but the 4th – 6th string is wound. Each individual string is of a different thickness, and they each have a specific note to be tuned to. The 12 string guitar is the alternative to this, because they have 12 strings to tune instead of six.
Electric guitar strings that are wound are created by rolling a string made of white metal around a centrally located string. The different types of material used for wrapping around the central string depend on the durability and tone wanted by the musician. Typically you will find that an electric guitar uses a nickel or nickel alloy material.
The thickness of the string is referred to as the gauge of the string. The guitar string is measured by fractions of an inch.
Light Gauge String
(.008 – .038) (.009 – .042) (.009...