Generally Accepted Accounting Principles (GAAP) are the rules that govern how accountants measure, process, and communicate financial information to ensure consistent accounting procedures are followed when preparing financial statements. The document outlines key GAAP concepts like the business entity concept, continuing concern concept, time period concept, and principles of consistency, conservatism, objectivity, materiality, and full disclosure. It also discusses the cost principle, revenue recognition convention, and matching principle for determining when to record the results of business transactions.