Water is a vital resource for both human life and the economy, and its use and management are critical security issues. The scarcity of water resources has adverse effects on the economy, ecology, and public health, leading to lower crop yields, increased food costs, reduced living standards, and a higher risk of conflict between states. Water security has become a major cause of conflict in recent times. This article provides a historical overview of the term water security and conducts a comparative analysis of the various definitions of water security presented by authors and organizations. The article examines the theories of scholars who have written about water security and concludes that it is a complex concept encompassing various aspects of ensuring the safety of water resources, including preventing pollution, ensuring access to clean drinking water, protecting water bodies, developing mechanisms for managing water resources, and preventing conflicts over water. Furthermore, this article analyzes water security within the framework of national security and provides examples from different regions to emphasize the importance of water for individuals and the state.