The deferred Mahr deserved for a woman

Q 2: I heard a question directed through phone, stating the following: There is a person who appointed for his wife a deferred Mahr (mandatory gift to a bride from her groom) that reached the Nisab (the minimum amount on which Zakah is due) but she did not receive it. Knowing that a Hawl (one lunar year calculated from the time a property reaches the minimum amount upon which Zakah is due) has passed on this, should the woman pay Zakah on it? The answer was: The deferred Mahr of a wife takes the same ruling as all her other property. Thus, she should pay Zakah on it if it reaches the Nisab and a Hawl has passed on it. If it is a debt owed by the husband, the Zakah due on it has the same ruling as Zakah on debts.My question is: What is the difference between Mahr and deferred Mahr? When should the Mahr be paid to the wife? As far as I know, the deferred Mahr is to be paid in case of Talaq (divorce pronounced by a husband) or the death of the husband. I have been married to my paternal cousin for 25 years and we are leading a peaceful life, praise be to Allah. My paternal uncle (may Allah be merciful to him) had imposed on me a deferred Mahr of five thousand dollars. (Part No. 8; Page No. 243

A: With regard to deferred Mahr, this is considered a debt owed to a wife by her husband, which she should pay Zakah on for every year if it reaches the Nisab or more, unless her husband is insolvent or the receiving of Mahr is conditioned by Talaq or the death of her husband, in which case no Zakah is due on her until she takes possession of it and one Hawl passes on it.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.