The words "Devil" and "Satan" are distinct but, much like "Hell" and "Hades", they end referring to the same thing. "Devil" can trace its roots to Diabolos, meaning "Slanderer" in Greek, while "Satan" is a Hebrew word meaning "Accuser, or Adversary". Interestingly, there is already a distinction made between any adversary and the adversary in Hebrew; when it is used to refer to any person who opposes another they are called "satan" whereas when it refers to the great adversary it is called "ha-satan". I'm not sure how it works out in the New Testament, but the understanding should be that when Jesus tells Peter to "get behind me, Satan", he's not calling him the Satan, but he is certainly evoking that level of severity.
Having said that, Satan and Devil can be seen more as Titles than a name given to a specific entity. There are many Devils and Satans, but there is certainly only the Satan, who is also the Devil. It's a bit of a Catholic issue to start making these distinctions and ordering them. I won't go so far as to say it's actually condoned by the Catholic church, just that it's an error to focus so much on it. Same with the ordering of the Angels and how Heaven works. It's at best speculation.