■ Distinction Between Nationality, Citizenship, and Permanent Residency
Countries around the world distinguish between citizens and foreigners based on nationality. South Korea follows this principle by defining a citizen as someone who holds South Korean nationality and a foreigner as someone who does not. (Article 2 of the Immigration Control Act)
Nationality refers to an individual's eligibility to become a citizen of a particular country. Many European countries, such as South Korea, Japan, China, and Germany, operate nationality systems. In contrast, countries such as the United States, Canada, Australia, and the United Kingdom operate citizenship systems. Individuals who hold citizenship in these countries have permanent loyalty and enjoy all the rights and benefits of citizenship. Therefore, citizenship and nationality can be considered similar in their legal nature and function, making it possible to view them as identical concepts in matters of nationality law. (Explanation of Nationality Law, Ministry of Justice, Immigration and Foreigners Policy Department, 2007, pp. 5-8)

For reference, permanent residency refers to the right or qualification granted by a foreign government to permanently reside in that country, regardless of nationality. For example, if a Korean obtains permanent residency in a foreign country, his or her status as a Korean continues to be maintained, but if the permanent resident voluntarily acquires foreign nationality or citizenship, his or her Korean nationality is automatically lost. According to the 「Overseas Koreans Act」, Korean nationals living in a foreign country who have obtained permanent residency are called overseas Koreans, and those who have acquired foreign citizenship (nationality) and live in a foreign country are called foreign nationality Koreans.

■ Congenital Nationality and Acquired Nationality
Countries around the world grant or deny nationality to individuals according to their own laws and principles. The reasons for granting nationality are generally divided into cases due to birth and cases due to reasons other than birth, such as naturalization. Congenital nationality is the nationality that a particular individual acquires at the time of birth. ‘Congenital nationality’ is roughly divided into lineage principle (individualism) and place of birth (territorialism) according to each country’s historical and cultural background. Countries based on civil law, such as Germany, France, Japan, and Korea, follow the principle of descent, while those based on common law, such as the United States, Britain, Canada, and Australia, follow the principle of place of birth. Ministry of Justice, Immigration Policy Headquarters for Foreigners, 『Nationality Law Commentary』, 2007, p. 44.

The Nationality Act of Korea divides the acquisition of nationality into “congenital nationality” through birth and “acquired nationality” through recognition, naturalization, or restoration of nationality. ‘Naturalization’ refers to the acquisition of Korean nationality by a pure foreigner who has never had Korean nationality after birth through a prescribed examination under the Nationality Act. “Recovery of nationality” refers to the former citizen of the Republic of Korea who, after losing or renunciating the nationality of the Republic of Korea, lives as a foreign citizen and then acquires the nationality of the Republic of Korea again.

■ Key Points on Acquiring South Korean Citizenship
Firstly, prior to the revision of the Nationality Act in 1997, South Korean citizenship could only be acquired by those who were born to fathers who were South Korean nationals, based on patriarchal lineage.
However, the Nationality Act was revised in December 1997 to adopt the principle of "parental lineage," allowing children born to a Korean and a foreign national in a legal marriage to automatically acquire South Korean citizenship at birth.
Secondly, in the case of a posthumous child whose father passed away before the child's birth, if the father was a South Korean national at the time of his death, the child can acquire South Korean citizenship at birth. Furthermore, if the parents' identity is unknown or if they do not have any nationality, a stateless person is created For example, if a child is born in South Korea as a result of an international marriage and it is discovered that the child's parents acquired citizenship through fraudulent means or a fake marriage, the child's citizenship may be revoked by administrative authorities, and the family relationship registration (formerly known as the "hojok") will be closed, resulting in statelessness.
, but the principle of exceptional birthplace jurisdiction is applied to prevent statelessness. To prevent such situations, exceptional birthplace jurisdiction is applied, and a child born in South Korea who is found abandoned (i.e., an abandoned baby) is presumed to have been born in South Korea (Article 2 of the Nationality Act). In cases where both parents are unclear, one can think of a single mother who gives birth to a child and abandons the child, and the child is later discovered and placed in a foster home or with a guardian, and their family relationship registration is recorded. In cases where both parents have no nationality, it refers to a case where a couple, who are both stateless, give birth to a child while temporarily residing in South Korea.
Third, in the case of a child born out of wedlock between a Korean national who is in a common-law relationship with a foreigner, if the child is a minor born to a foreign mother and a Korean father who is a citizen of the Republic of Korea, the child can acquire Korean nationality when the father reports the child's birth and registers the family relationship in the family register (previously known as the "hojeok") and then reports it to the Minister of Justice. For example, if a Korean man, A, who was working as a resident in Vietnam, meets Vietnamese woman B and has a child, C, in a common-law relationship, and if C is a minor and the father, Korean man A, reports his acknowledgement of the child to the Minister of Justice, C can acquire Korean nationality.
However, in the case of a child born out of wedlock between a Korean mother and a foreign father who is in a common-law relationship with the mother, the child acquires Korean nationality at birth. For example, if a stateless Korean man, A, residing in Uzbekistan, meets a Korean woman, B, while studying in Korea, and they have a child, C, without registering their marriage, then the child, C, born to a Korean mother, automatically acquires Korean nationality. In this case, the child can be registered in the family register following the mother's surname, as the father is stateless.
Fourth, to obtain Korean citizenship for her underage son K, born from her previous marriage with a Korean man, Chinese national P, who married a Korean man, needs to have her current husband complete the necessary information on the adoption application and register the adoption of her son K with the family registry office. Then, she can apply for naturalization to the Minister of Justice.
Fifth, foreign nationals who have not obtained Korean citizenship can obtain it by obtaining naturalization approval from the Minister of Justice. A naturalized citizen refers to a person who has acquired citizenship of another country through naturalization approval.
Sixth, under the Civil Code of Korea, a minor child of a foreigner can apply for Korean citizenship when either parent applies for naturalization approval. In this case, when the Minister of Justice approves naturalization for the parent, the minor child also obtains Korean citizenship. This is called "acquisition by accompanying".
Seventh, a person who was a former Korean national (Korean foreigner) and has lost or left Korean citizenship but wants to acquire Korean citizenship again can receive nationality restoration approval instead of naturalization approval. However, those who have caused harm to the country or society, those who have a questionable character, or those who have lost or left Korean citizenship for the purpose of avoiding military service are not eligible to apply for nationality restoration approval. Note that when a Korean national voluntarily acquires foreign citizenship, their Korean citizenship is automatically lost at the time of acquisition, and their family registry must be closed accordingly. If there is no record of loss of nationality in the family registry, a simultaneous application for nationality loss and restoration approval must be made when applying for citizenship.