GAAP - this stands for Generally Accepted Accounting Principles. It is the standard of guidelines and principles to be used by accountants in financial accounting.  Accounts rely on this set of standards when preparing financial statements for individuals. corporations and other entities.

The purpose of setting forth a standard set of rules and principles is to provide more uniformity in the field of accounting.  This in turn provides more confidence in the financial markets, especially when investors are relying on corporate financial statements and records that are so easily accessible on EDGAR and corporate websites.

GAAP is a fairly common term and caused some concern when Chinese companies started getting listed publicly in the United States but had financials that were not prepared in accordance with GAAP.