Unlike a divorce, an annulment invalidates a marriage. It is as if the marriage never occurred. If the annulment is successful, the marriage becomes legally void. In order to annul your marriage, the court needs sufficient proof including actual testimony from witnesses that the marriage meets one of the following factors:
When a marriage is annulled, it is declared null and void. You may consider yourself as never been married, and this may be beneficial to you for religious reasons (like if you are Catholic). Any children of the marriage will remain legitimate, and you remain responsible for the minor children of the marriage.
In a divorce, the marriage is dissolved, and your status afterwards will be divorced. The benefit of a divorce is that it will generally cost less because you can use no fault grounds rather than providing formal testimony with witnesses like an annulment.
In both cases the court will make orders for custody, visitation and child support and will divide marital property, marital debts, and determine maintenance (alimony).