The CIA Triad is the foundational model used to guide security decisions across the industry. Confidentiality means ensuring only authorized people can access certain information; Integrity means ensuring data isn’t altered or tampered with improperly; and Availability means ensuring systems and data are accessible to authorized users when needed. This lesson covers how nearly every security measure or policy can be understood in terms of protecting one or more of these three principles, making it a useful mental framework throughout the rest of the course.