The Fifth Amendment's Due Process Clause protects "life, liberty and property" from being taken away without Due Process.
Procedural Due Process means these things cannot be taken from you by the government unless there are proper court proceedings. In civil cases, the issue is whether you had notice and a hearing of the claims against you. In criminal cases, there are a whole panoply of rights which the U.S. Supreme Court has declared to be part of a proper court proceeding to punish you for a crime.
Substantive Due Process means these things (life, liberty and property) cannot be taken away from you at all, even if there is a proper court proceeding. These issues are almost always in civil matters where persons claim the government cannot do something to them such as force them to undergo medical treatment, refuse to allow a woman to have an abortion, refuse them a marriage license, etc.
Cal. Bar No. 104800
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Member: U.S. Supreme Court Bar
I am reluctant to cite to Wikipedia, but I will so in this situation. :-)
Procedural Due Process regards whether the process of adjudicating a person's rights is fair. Therefore, PDP concerns such issues as the right to fair notice, the right to an impartial judge, the right to elicit evidence and put on witnesses, the right to cross examine witnesses, etc.). PDP is predicated on the underlying law being valid.
Substantive Due Process is a broader concept. The underlying question in SDP is whether the law is valid, or whether it exceeds the limits of governmental authority. For instance, does a law against abortion exceed the government's power to legislate in that area because it conflicts with the right of a woman to control her body?
I hope this helps. Good luck!
Procedural due process would be whether getting an "F" for coming up with the answer to this question from Avvo was done without following school rules and procedures for punishments for cheating. Substantive due process would be whether going to Avvo for help with the answer is, in fact, cheating.
Providing this answer does not establish an attorney-client relationship.