Generally Accepted Auditing Standards (GAAS) are a set of guidelines for an auditor to conduct an audit. There are three sets of standards; general standards, standards of fieldwork, and standards of reporting.
The general standards (3) detail what the auditor's qualifications must be to perform the audit. The fieldwork standards (3) detail how the auditor must perform the audit. The standards of reporting (4) detail how an auditor must present the opinion in a report.
*Note: This is just a short version of the Generally Accepted Auditing Standards. To view the full set of standards issued by the AICPA: Click here!