The fundamental concepts of cryogenics are introduced in this chapter, and the broad impact on numerous fields, including industry, medicine, and scientific research, are explored. Key historical milestones in cryotechnology are discussed, along with the benefits of operating at extremely low temperatures. Special attention is given to the relevance of cryogenics in computing, setting the stage for deeper analyses in subsequent chapters. An overview of cloud computing and quantum computing systems along with the relevance to the cryogenic temperatures is also provided.