Introduction

Energy resources have played a pivotal role in the progress of human society, supporting everything from essential daily needs to large-scale industrial development and digital infrastructures. This chapter introduces the fundamental concepts of energy sources and resources, which provide the foundation for the discussions in the following chapters, while underscoring how technological advancements, economic factors, and policy frameworks shape their availability and exploitation. The organization of modern energy systems is also introduced, with particular focus on the distinction between primary and secondary energy, the role of conversion processes, and the importance of efficiency in resource utilization. The complex interdependence of energy demand and supply is discussed in relation to market dynamics, energy security, and socio-economic drivers. Finally, the chapter presents the Case Study Education methodology adopted in this book as an innovative pedagogical tool to bridge theory and practice, enhancing multidisciplinary problem-solving, critical thinking, and the use of computational tools in energy engineering.