This textbook presents basic concepts of electricity from a practical point of view. Providing the fundamental information upon which all subsequent electrical trades courses are based, it encourages an understanding of the use of various kinds of electrical devices. The book will help to build the knowledge base required by anyone who will go on to study construction wiring, electrical maintenance, or electrical distribution. A solid working knowledge of mathematics - including fractions, power of ten, solving simple equations, basic geometry and elementary trigonometric functions - is assumed.