This module introduces the fundamentals of cybersecurity in the context of digital water systems, with particular attention to IoT-based water quality monitoring, data transmission, cloud connectivity, and the cyber risks associated with increasing digitalization in the water sector. The module is designed to build both conceptual understanding and practical awareness of how digital water infrastructure operates, where vulnerabilities may arise, and how basic preventive and defensive measures can be applied. By linking water technologies, data flows, and cyber resilience, the module supports the safe and responsible digital transformation of the water sector.