The Republic of Korea, or South Korea as it is commonly known, is a democratic republic adopting the Presidential System. There are three branches of government that operate under a system of checks and balances between each branch. According to its constitution, the Republic of Korea shall seek the unification of Korea, formulate and carry out a policy of peaceful unification based on freedom and democratic principles.
The Executive Branch
This branch of government is headed by the President and he/she is directly elected by the people. He/she is only eligible to serve one term of five years. The president is not only the Head of State but also the Head of Government and Commander-in-Chief of the Armed Forces. The role of the President is to safeguard and unite their homeland peacefully. He/she can propose legislation, and has the power to veto bills, subject to a two-thirds override vote from the National Assembly. He/she has the power to declare war or declare a state of emergency or martial law, with the approval of the National Assembly
The Prime Minister is appointed by the President with the consent of the National Assembly in order to assist the President and under his/her orders to direct the Executive Ministries. He/she is not required to be a member of the National Assembly. The State Council is the chief executive body and cabinet of the Republic of Korea. It is composed of no less than fifteen and no more than thirty members, including the President and Prime Minister. Heads of the executive ministries (Ministers) are appointed by the President from among members of the State Council on the recommendation of the Prime Minister.
The Legislative Branch
South Korea has a unicameral Parliament which is known as the National Assembly and it holds the legislative power. The actual number of seats is determined by law but should not be less than 200 according to the Constitution. In 2020, the National Assembly is made up of 300 legislators who serve four-year terms, 253 of whom were elected from single-member constituencies and 47 from party-list seats.
The duties of the legislature are to pass or amend the laws of the country, to deliberate and decide the national budget bill and procedures of the administration, to determine types and rates of taxes, to ratify treaties and to approve state appointments. It also has the rights to consent to a declaration of war, the dispatch of armed forces to foreign states, or the stationing of alien forces in South Korean territory. Moreover, this branch of government has the mandate to impeach members of the executive if they are suspected of misconduct during their term in office. Impeachments need to be confirmed by the Constitutional Court.
The Judiciary Branch
The Judiciary branch of government consists of the Supreme Court, which is the highest court of the State, the Constitutional Court, and other courts at different levels.
The Supreme Court is the final court of appeal for all cases. The Chief Justice of the Supreme Court is appointed by the President with the consent of the National Assembly. There are 13 other Justices, appointed by the Chief Justice with the consent of the Conference of Supreme Court Justices. The term in office of the Chief Justice shall be six years and he shall not be reappointed, while the Justices of the Supreme Court with the same term in office may be reappointed.
The Constitutional Court is tasked to rule on the constitutionality of laws when the question arises. It is composed of nine Justices, all appointed by the President. However, three are appointed from persons selected by the National Assembly, and three from persons nominated by the Chief Justice of the Supreme Court. The President of the Constitutional Court is appointed by the President from among the Justices with the consent of the National Assembly. The term of office of the Justices of this Court is six years and they may be reappointed under certain conditions.
Local Governments
Although the Local Autonomy Act was passed in 1949, the country only adopted the local autonomous system of government in June 1995. The various local governments shall deal with administrative issues, especially welfare of local residents and property management, and enact provisions relating to local autonomy. The organization, powers, and election of local government councils are determined by law.
Local governments are divided into high-level and low-level local governments. Since 2012, there are 17 high-level local governments (i.e. Seoul Special City, six metropolises, eight provinces, and Jeju Special Self-Governing Province).
The number of low-level local authorities stands at 226 (75 cities, 82 counties and 69 districts). The heads of local governments and councilors are elected through direct election. The term for local government heads is four years, and they can be reelected for up to three terms. There is no limit on how many terms a local councilor may serve.
Sources:
https://www.constituteproject.org/constitution/Republic_of_Korea_1987.pdf?lang=en