Annulment and divorce are similar in that they both end marriage, but most couples are not eligible for an annulment. An annulment is a decree that a marriage was never valid. Some couples prefer this because they are legally able to erase what they believe was a mistake from their lives. Furthermore, annulment removes any obligation either spouse has to support the other after the end of marriage. If they never had a legal marriage, there’s no reason either is entitled to anything that belongs to the other.