The term String Gauge (strɪ́ŋ géǰ) refers to the weight and thickness of strings. Light gauge strings are considered the most versatile in sound and playability for a wide range of music styles, however they generate less sound output. Heavier gauge strings make a bigger sound but are harder to press down.

String gauge is measured in fractions of an inch and are described by the largest string size. Most guitars are shipped with what are termed Light gauged strings.  For acoustic guitars, this would mean that the string gauge for the 6th string (E) would be .012 inches, furthermore that package of strings would be called “twelves.” On electric guitars, the Light gauged 6th string (E) would be .010 inches and its package would be called “tens.”