Accountancy or accounting is the system of recording, verifying, and reporting of the value of assets, liabilities, income, and expenses in the books of account (ledger) to which debit and credit entries (recognizing transactions) are chronologically posted to record changes in value (see bookkeeping). Such financial information is primarily used by lenders, managers, investors, tax authorities and other decision makers to make resource allocation decisions between and within companies, organizations, and public agencies. Accounting has been defined by the AICPA as " The art of recording, classifying, and summarizing in a significant manner and in terms of money, transactions and events which are, in part at least, of financial character, and interpreting the results thereof."

Financial accounting is one branch of accounting and historically has involved processes by which financial information about a business is recorded, classified, summarized, interpreted, and communicated; for public companies, this information is generally publicly-accessible. By contrast management accounting information is used within an organization and is usually confidential and accessible only to a small group, mostly decision-makers. Open-book Accounting aims to improve accounting transparency. Tax Accounting is the accounting needed to comply with jurisdictional tax regulations. Accounting scholarship is the academic discipline which studies the theory of accountancy.