Often used for the end of a performance, event, or era, carrying a slightly dramatic or literary tone.
長かった会議もようやく終幕を迎えた。
The long meeting finally came to an end.
この事件は一つの時代の終幕を告げた。
This incident marked the end of an era.
終幕 is a native Japanese word for the closing act of a play, while フィナーレ is the loanword often used for the climactic finale of music or performances in general.
終幕 is the closing act or final curtain, the direct opposite of 序幕, which is the opening act.
Compound of 終 (shū, 'end') and 幕 (maku, 'curtain'), originally referring to the final curtain in a theatrical performance.