This lecture introduces the concept of superconductors and their applications in electronics, focusing on the formation of Cooper pairs and the properties of superconducting materials like Niobium and Aluminum. It also covers the fabrication techniques of Josephson tunnel junctions and different flavors of superconducting quantum bits, such as Transmons and Xmons. The lecture delves into the energy levels of harmonic oscillator circuits, resonator quality factors, and photon lifetimes, emphasizing the control of internal and external dissipation in LC oscillators. Additionally, it discusses the realization of transmission line resonators and the importance of resonator quality factors in quantum computing.