The declaration of a voidable marriage as null is annulment of marriage. Compared to divorce, annulment completely erases the marriage while divorce doesn’t. The process makes the marriage null and void as if there was no marriage in the first place. Such annulment of marriage petition can be filed under the Section 12 of Hindu Marriage Act.
While divorce ends a legal marriage, annulment removes all records, or a pre-existing marriage declaring it to be void and null. In other sense, as if the marriage never happened. In addition, divorce procedure, whether it is mutual consent divorce or contested divorce, takes more time depending upon the case complexity and parties settlement agreement. However, in the case of annulment of marriage, the procedure can be faster if the proper evidence can be produced for the grounds given for annulment of marriage.