The textbook "Electrical Engineering Circuits and Their Function" offers a comprehensive and detailed presentation of the operation of both classical and modern electrical engineering circuits. It serves as a reliable reference work for use in schools and businesses and is particularly suitable for preparation for skilled worker and journeyman examinations, as well as other forms of further education. With over 1000 illustrations, the complex subject matter is presented in a clear and understandable manner. The topics covered include, among others, feeding into the public grid, smart grids, wind energy, combined heat and power plants, and photovoltaics. This book is a valuable resource for anyone involved in electrical engineering who wishes to deepen their knowledge.