A style is referring to how you address a person in a formal manner. It varies on the status of a person. For example a married woman would be addressed as Mrs (Audio (USⓘ). A prince would be addressed as His Royal Highness. A male (regardless of being married) would be addressed as Mr.
Examples
Mrs Smith.
Mr Smith
Master Smith (Master is usually used by the oldest son in this case the oldest son of the Smith family).
↑Address meaning how someone would speak to or refer to another person.
References
12Maria Sifianou, Politeness Phenomena in England and Greece: A Cross-Cultural Perspective (Oxford: Oxford University Press, 1999), p. 65
↑Ambassador Mary Mel French, United States Protocol: The Guide to Official Diplomatic Etiquette (Lanham, MD: Rowman & Littlefield Publishers, Inc., 2010), p. 117