Although security and safety can both be traced back to antiquity, security was only recognised as a serious problem in the 1980s. At that time safety had already an accepted set of methods and solutions. The ‘new’ problem of security was therefore initially treated as a variant of safety and treated analogously, the predominant approaches being security by design, by prevention and by protection. Security, however, differs significantly from safety both because security breaches are intentional rather than haphazard, and because the secondary effects are more serious than the primary. This chapter considers these differences and concludes that security is not something that can be managed by itself or in isolation. The challenge is instead to manage for security so that a system or an organisation remains secure. © Springer Nature Switzerland AG 2021.