Refers to the rise and fall of the voice in speech, as in English. In Japanese linguistics, it is distinguished from アクセント (word accent).
Japanese intonation differs by region.
When asking a question, you raise your intonation.
In questions, the intonation rises at the end of the sentence.
Even the same word can change meaning depending on its intonation.
His Japanese is a bit hard to follow because his intonation sounds off.
I pay attention to my intonation when giving a speech.