“Mr.” and “Mrs.” are abbreviations for “Mister” and “Missus,” respectively. They are used as honorifics before the names of people, typically in formal or written contexts.
“Mr.” is used before the name of a man, regardless of his marital status. “Mrs.” is used before the name of a married woman. The abbreviation “Ms.” is used before the name of a woman whose marital status is unknown or irrelevant.