3 Staves in piano book. Whats the 3rd one?

Yes, the piano staff is the one with the bracket connecting the two. It's called the "grand staff". The other staff is probably above this one, correct? It's most likely a melody line, which comes from the highest notes of the grand staff's treble clef section. Are lyrics included in this piano book? If so, those are the pitches of those lyrics, written to accompany the piano.