What does it mean when you like more than one genre of music?

It means that you are broadminded, and don't just follow the current trends. It also means that you are more likely to give any new music you hear a chance to impress you, instead of automatically dismissing it as being different from what you like.

This could wind up spilling over into art, books, clothing, movies, etc. If you follow what interests you (without prejudging it first) and expose yourself to a wide variety of choices, in no time at all you'll have developed your own unique style.