IAS Stands for International Accounting Standards:
International Accounting Standards (IAS) were the first international accounting standards, were issued by the International Accounting Standards Committee IASC formed in 1973. The goal then as it remains today was to make it easier to compare businesses around the world and increase transparency and trust in financial reporting and in global trade and investment.
Globally comparable accounting standards promote transparency/ accountability and efficiency in financial markets around the world. This enables financial investors and other market participants to have knowledge of economic decisions about investment opportunities / risks and improves capital allocation for best results. Universal standards also significantly reduce reporting and regulatory costs / especially for companies with international operations and subsidiaries in many countries.
ISA stands for International Standard on Auditing:
This International Standard on Auditing deals with the independent auditor's overall responsibilities when conducting an audit of financial statements in accordance with ISAs
ISAs are written by an auditor in the context of an audit of financial statements .