Quick answer: AEO, AIO and GEO all describe the same shift: structuring content so AI answer engines can extract and cite it accurately, alongside traditional SEO for classic search rankings.
Search behaviour has fundamentally split. A growing share of queries never produce a click at all — they're answered directly inside Google's AI Overviews, or inside a chat interface like ChatGPT, Gemini or Perplexity. For content to matter in that world, it needs to be structured for extraction, not just readability.
The clearest shift is opening every page or article with a direct, self-contained answer to the core question — the exact block an AI system can lift and cite without needing the rest of the page. Supporting depth still matters for the human reader who continues past that first paragraph, but the opening now carries more weight than it used to.
Structured data — FAQPage, Article, Service, BreadcrumbList — gives AI crawlers an explicit, machine-readable map of a page's content and relationships. It doesn't guarantee a citation, but it removes ambiguity that might otherwise cause a page to be skipped in favour of a more clearly-structured competitor.
For most businesses, this means auditing existing content for a clear answer-first structure, adding schema markup site-wide, and treating FAQ sections as a core content asset rather than an afterthought at the bottom of a page.