The head of the state is the president. The Prime Minister is the head of the government, elected every four years and most of the time he/she happens to be the leader of the party that wins in the election.
The Republic of Turkey is a parliamentary democracy. The members of the Grand National Assembly are elected by the people. The President can assign the task of forming a government to anyone after elections. However, the individual who is assigned the task has to establish a cabinet that has the potential to be approved by the parliament. So, for that reason, the President assigns most of the time, the leader of the party which has the most seats in the parliament with reasoning that the leader of the party with the most seats can establish a cabinet, which is most likely to be approved by the parliament. However, sometimes due to the distribution of the seats. The individual assigned with the task fails. In that case the president assigns another individual. If this process fails a few times, a new election is called.
With the October 2007 amendment to the constitution President is elected by the popular vote. He/she serves for five years with the possibility of a second 5-year term if re-elected.
The prime minister with his cabinet is the executive branch of the government. The Parliament is the legislative branch. There is also a judicial branch of the government made of independent courts including a high court which takes up issues related to the constitution and called the Constitutional Court (similar in functionality to the Supreme Court in the US).
The most important decisions of the government are made by the National Security Council. The President presides over this council, the main members of which are the chief of the general Staff, the prime minister, the ministers of the foreign affairs, interior, national defense, and the commanders of the military branches.
The one of the main principles of the foreign policy of the Republic of Turkey is to not intervene the internal affairs of other sovereign governments. In return, the Turkish Republic’s other guiding principle is to expect other countries to respect its own sovereignty. Due to these guiding principles Turkey may look like a passive country when it comes to international issues and conflicts. Generally Turkey refrains taking sides, instead tries to bring the sides to a table for the conflict resolution.
Turkey is a member of many international organizations, amongst them NATO, OECD, and the Black Sea Economic Cooperation Organization and European Council are the significant ones.