What is the meaning of the abbreviation 'Ms.'?
Ms, like Mrs and Miss, is a contraction of the honorific "Mistress", which is the feminine of "Mister" or "Master". However, unlike Miss and Mrs., it does not presume the addressee's marital status. Ms. originated in the United States and was popularized in the 1970s. It is now the default form of address for business correspondence with a woman.
An MBA is the abbreviation for a masters in business administration. An MS is the abbreviation for a masters in science. The MBA is particular to business while the MS is a degree category which has numerous programs of study that fall under this category. In other words, an MS in math, engineering, biology, computer information systems, etc.