This document discusses information security and whether it is an art or a science. It begins with definitions of security and information security, focusing on protecting information systems and data. It then provides a brief history of information security, from its origins in code breaking during World War II to the increased threats in the modern internet era. The document outlines key information security concepts like confidentiality, integrity, and availability. It also discusses security services, information states, security countermeasures, and the importance of prevention, detection and response.