Google AI Overviews (AIO) is the AI-generated answer panel that appears at the top of certain Google search results. Launched globally in 2024 (originally as Search Generative Experience / SGE), AIO uses a Google-tuned variant of the Gemini model to compose an answer from classic Google search results.
The defining technical fact: AIO uses the same Google search index as classic Google Search, populated by the same Googlebot crawler. There is no separate AIO index. Pages ranking in the top 3 organic results are roughly 5-8x more likely to appear in an AIO citation for the same query than pages ranked 4-10. Classic SEO transfers directly.
The differences from classic SERP live in the answer-composition layer. AIO weights FAQPage schema, named-author E-E-A-T signals, Knowledge Graph entity grounding, and dateModified recency more heavily. A page that ranks well on Google but lacks these structural signals can still be skipped by AIO for the same query.
For measurement, Google Search Console broke out AI Overviews impressions and clicks as a separate report in 2025 — the canonical first-party source for AIO performance data.