It specifically refers to the traditional Filipino custom of singing love songs outside a loved one's window at night.
Other words that can be used include:
* "kundiman": A type of love song, often used in serenades.
* "awit": A general term for song, but can be used to refer to a serenade.
* "pagsasayaw": This literally translates to "dancing", but can be used to refer to a serenade that involves dancing.
While "harana" is the most accurate translation, the others can be used depending on the context.