Mrs :sed before a married woman's family name to be polite when you are speaking to her, writing to her, or talking about her
Ms :used before a woman's family name when she does not want to be called 'Mrs' or 'Miss', or when you do not know whether she is married or not .
Miss :used in front of the family name of a woman who is not married to address her politely, to write to her, or to talk about her
spoken used as a polite way of speaking to a young woman when you do not know her name .
Excuse me, miss, could I have another glass of water?
Longman Dictionary :-D