Which musical term signifies the end or closure of a piece?

The term that signifies the end or closure of a piece of music is "Fine." This Italian word directly translates to "end," and it instructs the performer that the piece is concluding. Commonly found in musical scores, this term marks the point at which the music should stop and indicates the completion of the composition.

In contrast, while "Coda" also refers to an ending, it specifically denotes a concluding passage that is added to the end of a piece to round it off, rather than serving as a direct indicator of where the piece ends. This distinction is key in differentiating between a formal close and an additional ending segment.

"Allegro" and "Vivace" are terms used to describe the tempo or speed of a piece, with "Allegro" indicating a fast, lively tempo and "Vivace" suggesting a brisk pace. These terms do not pertain to the structure or closure of a musical work. Thus, the correct term for indicating the end of a piece is "Fine," clearly marking the conclusion for performers.