An Autonomous Territorial Unit (ATU) is a region that has a degree of self-governance and operates independently from the central government. These units can make decisions on local matters, such as education, health, and infrastructure, while still being part of a larger state. The level of autonomy can vary significantly, depending on the laws and agreements in place. ATUs are often established to recognize the unique cultural, historical, or geographical characteristics of a region. Examples of ATUs include areas like Hong Kong in China and Catalonia in Spain. These regions have their own governing bodies and can enact laws that reflect the needs and interests of their local populations.