The purpose of this book is to provide a basic understanding of fixed assets and depreciation concepts. The text presents the fundamentals of depreciation, providing the necessary foundation for advanced studies. The book is primarily intended for those new to the area of depreciation and technically accurate for use by those with more experience in depreciation. Its orientation is towards depreciation accounting as a cost allocation concept, rather than a determinant of value, using the methods of historical life and net salvage analysis for gas and electric utility property. The basic underlying principle of utility depreciation accounting is intergenerational equity, where the customers/ratepayers who benefit from the generated service of assets pay all the costs for those assets during the benefit period which is over the life of those assets.