Citizenship through naturalization is a process by which someone who is already a citizen of one country is able to gain citizenship in a different country. This may or may not involve the person renouncing his or her initial citizenship, depending on the laws of each country. The process can vary from one country to another, though in general it involves living in a country for a particular period of time and learning about the culture and history of that country. Citizenship through naturalization also typically involves other measures as well, such as speaking at least one official language for a country and swearing an oath of allegiance.
While citizenship through naturalization is one way to gain citizenship in a country, it is not the only way to do so. The two most common means of gaining citizenship in a country are through jus sanguinis, which means “right of blood,” or jus soli, which means “right of birthplace.” When someone is born, he or she typically has citizenship in the country in which his or her parents are citizens; this is jus sanguinis. At the same time, someone may be a legal citizen of whatever country he or she is born in, which is jus soli.
It is possible, therefore, for someone to be born with dual citizenship, if born to parents who are citizens of a particular country while they are not in that country; otherwise, however, someone must typically gain citizenship through naturalization. Gaining citizenship through naturalization often begins with someone legally living and working in a particular country for a set period of time. In the US, for example, this length of time is five years, though it is only three years for someone married to a US citizen. The person must live and work in the country, learn about the history and government of the country, and learn the language of the country.
Once someone lives in a country long enough, he or she may then try to gain official citizenship through naturalization. This usually involves taking a test or examination to demonstrate that the person has learned the language of that country and knows about the history and society of the country. Once this is done, he or she may also have to go through interviews to ensure that he or she is of good moral character. After all of these steps are complete, the person may then need to take an oath of allegiance to gain citizenship through naturalization, which can involve renouncing any previous citizenship to other countries.