The Soviet Union signals its belief in the importance of electronics by perpetrating industrial espionage in more technologically-proficient nations. Paralleling the universally-held conviction of the decisive importance of electronics in national economic fortunes is to be found an equally compelling view that electronics is crucial to national defence and must be encouraged to flourish as a key constituent of defence industry. The products issuing from the collaboration of electronics with the defence sector are both profuse and striking: radar, computer, numerically-controlled machine tools, miniaturised components and graphics software all essentially owe their genesis to military needs or sponsorship. Electronics devices are simply implements that make use of electrons moving in a vacuum, gas or semiconductor. But maintaining that the electronics industry is the manufacture of electronics devices is something analogous to claiming that the manufacture of aerofoils suffices to explain the function of the aerospace industry. The chapter also presents an overview of the key concepts discussed in this book.