There is a distinct different in some states expunge does not mean seal or destroy. I thought I would add some law I have used in drafting record sealing motions in the past for a more specific answer.
For example here in Nevada, seal means sealed. Nevada provides that “all proceedings recounted in the record are deemed never to have occurred, and the person to whom [the order] pertains may properly answer accordingly to any inquiry concerning the arrest…and the events and proceedings relating to the arrest ....” NRS § 179.285. Nevada law is explicit in that “all proceedings recounted in the record are deemed never to have occurred, and the person to whom [the order] pertains may properly answer accordingly to any inquiry concerning the arrest, ... and the events and proceedings relating to the arrest ....” NRS § 179.285. State, Dept. of Motor Vehicles and Public Safety v. Frangul, 110 Nev. 46, 867 P.2d 397. Thus, the court record is absolutely sealed, criminal records does not leave any trace of the arrest or conviction and the defendant can say under oath he/she has never been arrested (for that offense at least).
Nevada record sealing is akin to expungement in the federal arena where it’s "the judicial editing of history." Rogers v. Slaughter, 469 F.2d 1084, 1085 (5th Cir.1972) and allows the Defendant to deny the existence of the arrest or events surrounding the case.
When records are ordered sealed, the effect of the order should “put the defendant back in the position he would have been in if the [constitutional] violation never occurred.” Nunes v. Mueller, 350 F.3d 1045, 1057 (9th Cir. 2003) quoting United States v. Blaylock, 20 F.3d 1458, 1468 (9th Cir. 1994).
In most states that is what record sealing aka expungement aka expunction does. Check with your local public defenders office for specifics on what your state offers you. If you are California, the Orange County Public Defender has a great link clearly stating what options are available between record sealing and expungement.
I would also add, in California, if the defendant can prove there was no reason to have arrested the defendant in the first place.
Specifically, Penal Code section 851.8 (b) requires “any law enforcement agency” to destroy their records. “[Penal Code] section 851.8 is for the benefit of those defendants who have not committed a crime. It permits those petitioners who can show that the state should never have subjected them to the compulsion of the criminal law -- because no objective factors justified official action -- to purge the official records of any reference to such action. . . ...” (People v. Matthews (1992) 7 Cal.App.4th 1052, 1056.) (Emphasis added)
In People v. Scott M. (1985) 167 Cal. App. 3d 688, 700 [“Section 851.8 is for the benefit of those defendants who have not committed a crime.”].) Factual innocence may be determined based on circumstances at the time of arrest or any meritorious defense. Recent case law establishes the pivotal time for viewing the evidence is when the motion is heard. The statutory language “necessarily means that the existence of reasonable cause depends on the current evidence rather than simply the evidence that existed at the time that the arrest and prosecution occurred.” (People v. Laiwala, 143 Cal. App. 4th 1065, 1068 & n. 3 (2003) (emphasis added).
Keep in mind in California, "expunge" does not mean to seal or destroy, but officially dismisses the conviction - leaving the public record intact.