First/given, middle, and last/family/surname with John Fitzgerald Kennedy as example. This shows a structure typical for English-speaking cultures (and some others). Other cultures use other structures for full names.
A surname, family name, or last name is the portion (in some cultures) of a personal name that indicates a person's family (or tribe or community, depending on the culture). Depending on the culture, all members of a family unit may have identical surnames or there may be variations based on the cultural rules.
In the English-speaking world, a surname is commonly referred to as a last name because it is usually placed at the end of a person's full name, after any given names. In many parts of Asia, as well as some parts of Europe and Africa, the family name is placed before a person's given name. In most Spanish-speaking and Portuguese-speaking countries, two surnames are commonly used and in some families that claim a connection to nobility even three are used.
Surnames have not always existed and today are not universal in all cultures. This tradition has arisen separately in different cultures around the world. In Europe, the concept of surnames became popular in the Roman Empire and expanded throughout the Mediterranean and Western Europe as a result. During the Middle Ages this practice died out as Germanic, Persian, and other influences took hold. During the late Middle Ages surnames gradually re-emerged, first in the form of bynames (typically indicating individual's occupation or area of residence), which gradually evolved into modern surnames. In China surnames have been the norm since at least the 2nd century BC.
A family name is typically a part of a person's personal name which, according to law or custom, is passed or given to children from one or both of their parents' family names. The use of family names is common in most cultures around the world, with each culture having its own rules as to how these names are formed, passed and used. However, the style of having both a family name (surname) and a given name (forename) is far from universal. In many cultures, it is common for people to have one name or mononym, with some cultures not using family names. In most Slavic countries, as well as other countries including Greece and Iceland, for example, there are different family name forms for male and female members of the family. Issues of family name arise especially on the passing of a name to a new-born child, on the adoption of a common family name on marriage, on renouncing of a family name and on changing of a family name.
Surname laws vary around the world. Traditionally in many European countries for the past few hundred years, it was the custom or law that a woman would on marriage use the surname of her husband and that children of a man would have the father's surname. If a child's paternity was not known, or if the putative father denied paternity, the new-born child would have the surname of the mother. That is still the custom or law in many countries. The surname for children of married parents is usually inherited from the father. In recent years there has been a trend towards equality of treatment in relation to family names, with women being not automatically required or expected, or in some places even forbidden, to take the husband's surname on marriage, and children not automatically being given the father's surname. In this article, family name and surname both mean the patrilineal surname, handed down from or inherited from the father's, unless explicitly stated otherwise. Thus, the term "maternal surname" means the patrilineal surname which one's mother inherited from either or both of her parents. For a discussion of matrilineal ('mother-line') surnames, passing from mothers to daughters, see matrilineal surname.
In English-speaking cultures, family names are often used by children when referring to adults, but are also used to refer to someone in authority, the elderly, or in a formal setting, and are often used with a title or honorific such as Mr., Mrs., Ms., Miss, Doctor, and so on. It is also common in English-speaking cultures for individuals to be referred to by their surname instead of their given name by their friends. Generally the given name, first name, forename, or personal name is the one used by friends, family, and other intimates to address an individual. It may also be used by someone who is in some way senior to the person being addressed. This practice also differs between cultures; see T–V distinction.
The study of proper names (in family names, personal names, or places) is called onomastics. A one-name study is a collection of vital and other biographical data about all persons worldwide sharing a particular surname.
Since family names are normally written last in European societies, the terms last name or surname are commonly used for the family name, while in Japan (with vertical writing) the family name may be referred to as upper name (ue-no-namae (上の名前)).
When those from Japan, Taiwan and Hong Kong write their personal name in the Latin alphabet, it is common to reverse the order of the given and family names for the convenience of Westerners, so that they know which name is the family name for official/formal purposes. Reversing the order of names for the same reason is also customary for the Baltic Fennic peoples and the Hungarians, but other Uralic peoples traditionally did not have surnames, perhaps because of the clan structure of their societies. The Samis saw no change or a transformation of their name. For example: some Sire became Siri, Hætta Jáhkoš Ásslat became Aslak Jacobsen Hætta — as was the norm. Recently, integration into the EU and increased communications with foreigners prompted many Samis to reverse the order of their full name to given name followed by surname, to avoid their given name being mistaken for and used as a surname.
Indian surnames may often denote caste, profession, and village and are invariably mentioned along with the personal names. However, hereditary last names are not universal. In Indian passports the surname is shown first. In telephone directories the surname is used for collation. In North Indian states the surname is placed after given names where it exists. In parts of south India, surname is placed before personal name and in most cases it is only shown as an initial (for example 'S.' for Suryapeth).
In English and other languages like Spanish—although the usual order of names is "first middle last"—for the purpose of cataloging in libraries and in citing the names of authors in scholarly papers, the order is changed to "last, first middle," with the last and first names separated by a comma, and items are alphabetized by the last name. In France, Italy, Spain, Belgium and Latin America, administrative usage is to put the surname before the first on official documents.