I was under the impression that probation is for someone who has not been sectenced to prison and parole is for someone who has. I know out my way there different types of probation for unsupervised to ISP(intence supervised probation) and if you go to the joint then theres diffent level's of parole. I can only speak for state cases though i have no idea how the fed's work but i assume it's along the same guidelines.