Accounting systems provide financial information critical to managing, valuing, and regulating all types of organizations around the globe. Despite their many variations, all accounting systems are built on a common foundation. This foundation relies on such economic concepts as assets, liabilities, and income to convey financial information, as well as the double-entry system of debits and credits to accumulate and organize financial data. After developing the foundation, we will explore the generally accepted accounting principles that underlie financial statements, develop an understanding of what can be gleaned from those statements (that is, develop an understanding of how the accounting numbers relate to the true economic events that give rise to the numbers), develop an appreciation of what is left out of the financial statements, and, finally, discuss how accounting numbers are used in various financial and management tasks (e.g., valuation). While the focus is on reporting in the United States, international examples are also considered.