A security audit focuses on whether your software has vulnerabilities that could be exploited – injection flaws, insecure dependencies, authentication weaknesses, and similar technical risks. The question it answers is: how easy would it be for someone to break this?
A compliance audit focuses on whether your software meets specific regulatory requirements – HIPAA, PCI DSS, ISO 27001, SOC 2, or others. The question it answers is: does this software satisfy the rules we’re required to follow?
In practice, they overlap significantly. Most compliance frameworks require strong security controls, and a well-secured application is usually easier to make compliant. We often conduct both in a single engagement, since the codebase is already open and the incremental effort is modest.
Reference
NIST Cybersecurity Framework – NIST – nist.gov