ABSTRACT
This chapter introduces the reader to critical infrastructures and their protection. To this end, it presents these concepts in relation to four locations: the European Union, the United States, the United Kingdom, and Poland. It then seamlessly transitions into the concept of critical network infrastructures. They comprise three basic networks: power, road, and ICT. The chapter then explores resilience, vulnerability, and risk in relation to technical systems and critical infrastructures. The final section discusses the fundamentals of reliability for complex technical systems, including two-state, ageing, multi-state, non-renewable, and renewable systems. This chapter provides a general introduction to the rest of the book.
