Comment by Albright

"Sealed" implies the record is reasonably inaccessible to the general public, but still easily accessible to law enforcement. When you are arrested, law enforcement, and especially prosecutors, will be very interested in what you have been convicted before previously, especially if your state has a "three strikes" law (where you can end up with life in prison for your third felony conviction, regardless of the seriousness of the felonies) or something similar.