What's an expungement? An expungement is a method for you to get your record sealed for most practical purposes and therefore, give you a greater possibility to get employment and advance within your selected career.
After an expungement is granted, if the file is exposed one would see it, but inside the file it would show that you pled not guilty and the charges against you had been dismissed. Additionally, if you get an expungement, govt. agencies will still have knowledge of the criminal activity, but private businesses will not.
If you had a DUI case and the results had been expunged and you get another DUI for example, the prosecution would know about the prior offense and could use the previous conviction against you. Furthermore, if given an expungement, future companies may not find out about the expungement, investigate it or hold it against you. If they do they would be subjecting themselves to criminal prosecution.