This document provides an overview of auditing and assurance services. It defines auditing as a systematic process of objectively obtaining and evaluating evidence to ascertain the degree of correspondence between assertions and established criteria. The key relationships are discussed between assurance services, attestation engagements, and auditing, with auditing focused specifically on financial statements. The roles and responsibilities outlined in the Sarbanes-Oxley Act are summarized, including management's responsibility for financial reporting and the prohibitions on certain client services. The types of audits, auditors, and organization of the accounting profession are also briefly described.