The term "nation state" refers to a country considered as a sovereign political entity that is represented in international affairs by one government. It implies that the people living within its borders share common culture, language and history which distinguishes them from other nations or ethnic groups. A nation-state has the power to regulate domestic and foreign policies, maintain law and order, and provide basic services such as education, healthcare, and security for its citizens. The concept of a nation state emerged in Europe during the 19th century when many European countries unified their separate kingdoms into single political entities based on shared national identity. Today, there are around 200 independent nation-states that belong to the United Nations, each with its own unique history and culture.