Why do we have fifteen different books for Adele 21? Why do we run to four different places in the store when you're looking for Taylor Swift? Different formats, my friend, different formats. Here's a quick guide to the most common formats you'll see when you're looking for non-classical music:
Piano/Vocal/Guitar (PVG) or Piano/Vocal/Chords (PVC)
This is the format you'll see most frequently in our "personality songbook" section. The music is written for a vocal line with a piano accompaniment, and shows guitar chord charts above the vocal line. Most often the vocal line is written into the piano part so that you don't need to sing along.
Fun fact: Back in the day (the day being the 20s-40s), sheet music and books in this format often gave ukulele chords instead of guitar chords. It's not uncommon to see accordion chords in old sheet music as well. With the insanely high level of interest in ukulele right now, I wouldn't be surprised if we start seeing more music that includes uke chord charts along with or instead of guitar chords. Great book in this format: Adele 21