A Korean name consists of a family name followed by a given name, as used by the Korean people in both North Korea and South Korea. In the Korean language, ireum or seong-myeong usually refers to the family name (seong) and given name (ireum in a narrow sense) together.
Traditional Korean names typically consist of only one syllable. There is no middle name in the English language sense. Many Koreans have their given names made of a generational name syllable and an individually distinct syllable, while this practice is declining in the younger generations. The generational name syllable is shared by siblings in North Korea, and by all members of the same generation of an extended family in South Korea. Married men and women usually keep their full personal names, and children inherit the father's family name.
The family names are subdivided into bon-gwan (clans), i.e. extended families which originate in the lineage system used in previous historical periods. Each clan is identified by a specific place, and traces its origin to a common patrilineal ancestor.
A given name (also known as a personal name, first name, forename, or Christian name) is a part of a person's full nomenclature. It identifies a specific person, and differentiates that person from other members of a group, such as a family or clan, with whom that person shares a common surname. The term given name refers to the fact that the name is bestowed upon, or given to a child, usually by its parents, at or near the time of birth. This contrasts with a surname (also known as a family name, last name, or gentile name), which is normally inherited, and shared with other members of the child's immediate family.
Given names are often used in a familiar and friendly manner in informal situations. In more formal situations the surname is more commonly used, unless it is necessary to distinguish between people with the same surname. The idioms "on a first-name basis" and "being on first-name terms" allude to the familiarity of addressing another by a given name.