There is a very significant difference. In a deferred prosecution the DA holds the case open while you complete the agreement. If you complete it the case is dismissed. The con to going this way is you remain on bond until the agreement is complete. So any violations of bond is a bail jump. With deferred judgment you plead guilty up front before the judge and the judge holds open entry of conviction pending completion. The pro is you are off bond but the huge con is if you fail the agreement. In a deferred prosecution you still have your right to a trial and all your defenses. In a deferred judgment that is all done. You already pled guilty. All that needs to done at the point is a sentencing. That is why I favor deferred prosecutions and DAs like the deferred judgments.
The first answer is great. I would add one thing. There is a special type of differed prosecution agreement called a DAGP, or differed acceptance of a guilty plea. This type of agreement falls between the traditional Deferred Judgment and Deferred Prosecution agreement. The law considers a DAGP a type of deferred prosecution but is probably more similar to a deferred judgment for the defendant's purposes. A DAGP wasn't initially invisioned by statute (if you look to the statutes for a description, you will see only two types of agreements, Deferred Judgment and Deferred Prosecution) but some case law discusses how a DAGP works.
I see a lot of DAGP agreements in cases where there is an ordinance (non-criminal) or a similar misdemeanor. A DAGP requires the defendant to enter a guilty plea, but then the judge does not accept the plea. Instead, the defendant is given a chance to complete the agreement. If successful, the defendant is often given a misdemeanor instead of a felony or just an ordinance. When the agreement is successfully completed, the defendant typically doesn't have to do anything, as any "punishment" for the end result is part of the agreement. If the defendant violates the agreement, the judge can, but isn't absolutely required to accept the plea of guilty. Also, unlike in a Deferred Judgement, if a defendant violates the agreement, there is still a chance to argue about sentencing.
As far as the two traditional scenarios for Deferred Judgment versus Deferred Prosecution, the first answer explains pretty much everything, except that when the defense and State are arguing about which one is appropriate, often times the parties split the baby and agree to a DAGP.
In Appleton, they call them DPAs (deferred prosecution agreements); however, you enter a plea but the court doesn't convict you. It sits open. If you successfully complete the terms, it gets dismissed. If it is revoked (which requires the state to file a motion and for the court to agree), then you get convicted and sentenced on the charge you plead to.
In accordance with the Avvo community guidelines, this communication does not constitute "legal advice", nor does it form an attorney-client relationship. You should seek counsel in your geographic area regarding any specific questions.