It could refer to a few things:
* A song title: There are several songs with this title, including a popular one by the Mexican group Mana.
* A phrase or expression: It might be used to indicate that a specific phrase or sentence consists of only three words.
* A book or film title: "Tres Palabras" could be the title of a work that focuses on the power of three words.
Without more context, it's difficult to determine the exact meaning. Can you provide more information about where you encountered this phrase?