Definition & Meaning of "octave"

What is an "octave"?

An octave is the interval between one musical pitch and another pitch that is either double or half its frequency. In simple terms, it is the distance between two notes with the same name but at different pitches. For example, if you play a C note, the next C note higher or lower is an octave away. The sound of these notes is perceived as very similar, though one is higher or lower than the other. Octaves are fundamental in music for creating harmony and structure, and they help in organizing the musical scale.