IAS (International Accounting Standards) and IFRS (International Financial Reporting Standards) are international accounting standards that are issued by the International Accounting Standards Boards (IASB) and must go through an approval process. These are then accepted in the form of the regulation of the European Commission to the European Parliament and the Council.
The aim of IAS/IFRS is to achieve a high degree of comparability and transparency of financial statements in a global scale.
By the EU Council Regulation from January 1, 2005, the companies with publicly-traded securities in the European Union must draw up the financial report under the standards IAS/IFRS.
US GAAP is the equivalent accounting standard used in the United States.