This textbook sets out to enable readers to understand fundamental
aspects underlying quantum macroscopic phenomena in solids, primarily
through the modern experimental techniques and results. The classic
independent-electrons approach for describing the electronic structure
in terms of energy bands helps explain the occurrence of metals,
insulators and semiconductors. It is underlined that superconductivity
and magnetism can only be understood by taking into account the
interactions between electrons. The text recounts the experimental
observations that have revealed the main properties of the
superconductors and were essential to track its physical origin. While
fundamental concepts are underlined, those which are required to
describe the high technology applications, present or future, are
emphasized as well. Problem sets involve experimental approaches and
tools which support a practical understanding of the materials and their
behaviour.