This well-established handbook for electrical engineering engineers serves as the first part of the established book series 'Electrical Machines' and provides a comprehensive introduction to the fundamentals of electrical machines. The structure and operation of the main types of electrical machines - transformers, direct current machines, induction machines, and synchronous machines - are explained in a way that is understandable for beginners while maintaining exemplary scientific accuracy. The present tenth edition has been supplemented with sections that reference current technological developments. Special sections have been dedicated to the characteristics of permanent magnet synchronous machines and synchronous reluctance machines, reflecting their growing importance, as well as to the requirements for energy efficiency. The treatment of induction machines has been addressed without neglect.