The Materials Science course is intended for students in the lower years of bachelor's studies in technical fields. It summarizes findings from the crystal structure of solids, and the thermodynamics of solids. It describes the behaviour of one-component and two-component systems, of which the iron-carbon system, according to which steel and cast iron crystallize, is discussed in more detail. It deals with both the equilibrium state of the system, but also the state that arises under non-equilibrium cooling conditions. Basic tests of mechanical properties and the essence of mechanical properties are explained within the course. Strengthening mechanisms and basic procedures for the heat treatment of materials are briefly described. As part of the introduction to the study of materials, individual groups of technical materials – metals, ceramics, polymers, and composites – are characterized in terms of their distribution, structure, properties, and use. The subject aims to connect theoretical knowledge about the internal structure of materials and its influence on the properties and subsequent application of materials in practice.