Authentic cadence is a musical term referring to the ending of a phrase, which can be perceived as a rhythmic, melodic, or harmonic change. It can mark the demarcation of a half-phrase, section, or entire movement. The term "cadence" comes from the Latin "cadere" meaning "to fall" and was originally associated with the stepwise descent of the tenor part in late medieval polyphony. In tonal music, the authentic cadence is one of four principal types of harmonic cadences, which incorporate the dominant and tonic triads. The perfect cadence—a strong type of authentic cadence—is characterized by the upper voice proceeding stepwise upward or downward to the tonic note, while the lowest voice skips from the dominant note upward a fourth, or down a fifth to the tonic note. The half cadence—another common type of authentic cadence—ends the phrase on a dominant chord, implying the continuation of another phrase ending with an authentic cadence.
Read more about authentic cadence in our article on authentic cadence exemplified by The Beatles songs.