Direct answer: SEO focuses on helping search engines discover, understand and surface webpages in search results. AIO focuses on making the information on those pages easy for AI systems to retrieve, understand, verify and cite. The two disciplines overlap and should be implemented together.
SEO and AIO share the same foundation
Both depend on accessible pages, clear information architecture, descriptive titles, useful content, internal links, canonical URLs and reliable technical delivery. AIO does not eliminate these fundamentals.
Where the emphasis differs
A simple example
A service page optimized only around a phrase may still leave important questions unanswered. An AIO-oriented page explicitly defines the service, explains who it is for, states what is included, distinguishes it from related services and links to supporting information. That clarity also benefits human visitors and conventional SEO.
Which should a business prioritize?
A business website should support both. Search engines remain a major discovery layer, while AI-powered search increasingly uses indexed web information as grounding for generated answers.