The dictionary-reference book contains about 1,500 terms, definitions and basic concepts related to commercial activities in the field of electricity, including technical, technological, economic and civil aspects. All terms are accompanied by references to the relevant standards (55 state and international standards were used), legislative, regulatory legal acts, regulatory and technical documents, reference books and other sources. The dictionary-reference book is intended for managers and specialists of all subjects of the electric power industry, including operational, energy supply, design , research, installation and commissioning organizations, as well as for personnel of Rostechnadzor bodies. Can be recommended to students of energy universities.