This course aims to introduce students to the key concepts in the study of security. It discusses security actors, their environment as well as the approaches to the study of security. The course further seeks to demonstrate that security is a broad concept that affects every facet of human existence. Hence, the levels of analysis that are emphasized in the course range from the individual to the collective in a bid to, inter alia, explain human security, regime security, military security, economic security, environmental security, energy security and cyber security. A key component of the course relates to the need to understand how social issues can gradually get securitized as they gain more and more security interest.