A Special Administrative Region (SAR) is a distinct area within a country that maintains a high degree of autonomy, especially in its legal and economic systems. SARs operate under the principle of "one country, two systems," allowing them to have their own laws and governance while still being part of the larger nation. Examples of SARs include Hong Kong and Macau, both of which are part of China. These regions have their own currencies, legal systems, and immigration policies, enabling them to function independently in many aspects while still adhering to the overarching sovereignty of the country.