Nanoelectronics provides an accessible introduction for prospective and practicing electronic engineers, computer scientists and physicists. The overview covers all aspects from underlying technologies to circuits and systems, reflecting the fact and challenge that nanoelectronics requires not only minute structures but also innovative systems for the effective integration of the billions of devices. On the system level, various architectures are presented and important features of systems, such as design strategies, processing power, and reliability are discussed. Many specific technologies are presented, including molecular devices, quantum electronic devices, resonant tunnelling devices, single electron devices, superconducting devices, and promising schemes for DNA and quantum computing. The book also compares these devices with current silicon technologies and discusses limits of electronics and the future of nanosystems.