What is octave definition?

Octave is a term used in music to describe the interval between two notes where the higher note has twice the frequency of the lower note. It is also used to describe a range of notes spanning eight diatonic degrees in a musical scale. For example, if the note A has a frequency of 440 Hz, then A an octave higher would have a frequency of 880 Hz. The term "octave" comes from the Latin word "octavus" meaning "eighth," as there are eight notes in a diatonic scale. The octave is considered to be a fundamental element in the structure of musical harmony and is essential to the understanding of musical intervals and chords.