“Res publica” is a Latin phrase that means “public affair” or “public thing.” It refers to a government system in which power is held by the people or their representatives. The term is commonly related to the concept of a republic, where the state is regarded as a public matter, not the private concern of rulers. In a res publica, decisions about governance and the common good are made collectively, keeping the interests of the public at large in mind. This idea has been influential in political theory and has been a crucial component of many democratic systems throughout history.