What is the name of a passage at the end of a piece of music that concludes it effectively?

The term that refers to a passage at the end of a piece of music, which effectively concludes it, is called a coda. A coda serves as a concluding section that often summarizes or brings closure to the themes explored throughout the composition. This section can vary in length and complexity and is intended to reinforce the piece's overall message or musical ideas.

In contrast, an exposition typically refers to an initial section in sonata form, where main themes are introduced. A bridge generally functions as a transitional passage within a piece of music, linking different sections or themes rather than concluding them. An introduction, as the name suggests, serves to introduce the music that follows and sets the stage for what is to come, rather than providing a closure.