This lecture covers the fundamental concepts related to the electrical and magnetic properties of materials, focusing on topics such as electric dipoles, semiconductor behavior, electrical conductivity of metals, doping of semiconductors, dielectric properties, and magnetic phenomena. It explains the influence of temperature on electrical resistivity, the role of impurities in conductivity, and the behavior of materials in magnetic fields. Additionally, it discusses the optical properties of materials, including reflection, absorption, and transmission of light, as well as the characteristics of semiconductors and optical fibers.