A compound bow has letoff. When fully drawn the draw weight is much less than the full draw weight of the bow. The lower number is the pressure you will feel at full draw. The higher number is the pressure the arrow will get right before it leaves the bow.
This is not correct. The range of 55-70# is because the draw weight on the bow is adjustable via the tiller bolts. The letoff is expressed as a percentage. If the bow is set to 60# and has a 75% letoff then the peak draw weight is 60# and the holding weight at full draw is 15# (60# - 75%).