Online privacy is a critical aspect of our digital lives, involving the control and protection of personal information in virtual spaces. This unit explores key concepts like data privacy, confidentiality, and anonymity, while examining the historical context of online privacy from early internet days to recent data breaches and regulations. The psychological theories underlying privacy behaviors are discussed, including privacy regulation and communication privacy management. The unit also delves into online behavior patterns, privacy concerns, and their impact on mental health, offering insights into protection strategies and ethical considerations surrounding digital privacy in our interconnected world.