Short version: An SEO audit is a structured review of how well a website can be found, understood, indexed, and trusted by search engines.
It usually checks technical SEO, crawlability, indexing, page structure, internal links, content quality, search intent fit, metadata, redirects, and competing pages. A good audit separates urgent blockers from improvements that can be planned over time.
The goal is not to collect warnings for their own sake. A useful SEO audit explains what is hurting visibility, what matters commercially, and which fixes should happen first because they can change real organic performance.
In practice, the audit should end with a prioritized action list, because a business needs to know which technical, content, or authority issue deserves attention first.
Related terms: Technical SEO, Content audit, and Web audit.