Rate & Weight Function

Hello,
I just noticed some songs played 100 times while others only 6 plays and then I noticed that some songs had only a weight number or only a rate number or both and others both empty. Maybe when those songs were added was different versions of software making some have and other not, so I changed all songs for now to 5 and 5 so they are all equal until I understand logic.

Now I need to understand function as to numerical value and its logic so I can make some songs play more than others but still play.

Weight number works where if it is higher number than other song numbers it gets played more or less than the other songs?
Rate number works where if it is a higher number than other song numbers it gets more plays or less plays than other songs?

Using below with the 6 songs having values below who gets played more than the other
Song 1 rate=5 weight 5 play position=?
Song 2 rate=10 weight=5 play position=?
Song 3 rate=10 weight=10 play position=?
Song 4 rate=5 weight=10 play position=?
Song 5 rate=1 weight=10 play position=?
Song 6 rate=10 weight=1 play position=?

Than you for any explanations!