Those are two kind of different things but are closely related. There are rules for how many guys you can sign which basically assumes that you are giving a scholarship to everyone who signs. So how many you can sign is a function of how many guys that are still on the team are on scholarship. You can have up to 85 scholarship players and can over-sign by 3 in February so current scholarship players plus the number you have signed in February is a max of 88. I think you are also only supposed to be able to sign 25 in a given class but that number is flexible because early enrollees can be counted back towards the previous class.
The actual scholarship limit of 85 only comes into effect when guys actually make it to campus. That's why you can over-sign by 3 (88) as long as you're back down to 85 by the time most guys show up in June. It gives you a little wiggle room as you usually have a couple guys decide to transfer after spring practice. But if someone you signed doesn't actually make it to campus, that scholarship is available to someone else. It either helps you get down to 85 or can be given to a walk-on or transfer. The only time you actually lose a scholarship is if the player enrolls in classes and then leaves school for some reason. Once they start classes for the semester, their scholarship can't be given to anyone else. This happened a couple years ago (Suttles?) where the guy was here for a week and then left but no one could use that scholarship for that semester.
