The hole spacing of squat rack is the distance in inches from the center of one hole to the center of the next hole:
Smaller hole spacings can be better
Smaller hole spacing can be better because they allow for more fine tuning of your safety spotter arms and j-hooks. However, often racks with smaller hole spacing are more expensive as well.
What is Westside Hole Spacing?
Westside Hole Spacing is when the holes are 2 inches apart at the top and the bottom of the rack and then 1 inch apart near the middle of the rack.