The structure of matter is intimately related to the fundamental role played by many-fermion systems. The development in the last few decades of the microscopic many-body theory of correlated fermion systems has been a fertile ground not only for spectacular achievements in basic science in various areas of research, but also for technological applications. Among the numerous phenomena discovered and studied in systems of many fermions, one can cite the superconductivity in metals, the superfluidity in 3He, nuclear matter and nuclei, the quantum Hall effect, the giant resonances in nuclei,...