State sovereignty refers to the authority of a state to govern itself without external interference. It is a foundational principle in international relations, signifying a state's control over its territory, laws, and governance. State sovereignty is crucial as it underpins the principle of non-interference, allowing states to engage in diplomatic relations and treaties autonomously. Challenges to state sovereignty can arise from globalization, international law, and humanitarian interventions, prompting debates about the balance between national authority and collective global responsibilities.