Network, service, and application management today faces numerous challenges, ones that older ways of doing things cannot solve. The concept of policy-based management (PBM) addresses some of these problems and offers possible solutions. It provides a system-wide view of the network and its services and applications, and shifts the emphasis of network management and monitoring away from specific devices and interfaces toward users and applications. This chapter describes the technology on the policy-based management paradigm which is consideredrelevant for providing a common base for researchers and practitioners who need to understand the current status of this emerging technology and how it can be applied to the Web and information systems security field.