A single-party system is a political structure where only one political party is allowed to hold power and govern the state. In this system, other parties may be banned or severely restricted, limiting political competition. This often leads to a lack of democratic processes, as the ruling party controls the government and decision-making without opposition. Countries with a single-party system, such as China with the Communist Party, often justify this structure by claiming it promotes stability and unity. However, critics argue that it can lead to authoritarianism, where citizens have little to no say in their governance and political freedoms are suppressed.