What's the core difference?
SEO competes for position in a ranked list; the win is a click. GEO competes to be a source the model summarizes and names; the win is a citation inside the answer. In search, the page is the destination. In an AI answer, the answer is the destination and your citation is the path back to you.
What do they have in common?
More than you'd think. Both reward crawlable, fast, well-structured pages; clear, authoritative, accurate content; and good information architecture. The technical hygiene that helps search — clean HTML, sensible headings, structured data — also helps models parse and trust you. GEO doesn't throw out SEO; it builds on the same foundation.
A page optimised for GEO tends to rank well in traditional search too, because both reward clear, authoritative, well-structured content. You don't have to choose.
Where do they diverge?
They diverge in emphasis. GEO leans harder on self-contained, quotable passages, question-shaped structure, explicit sourcing, and entity coverage, because a model is deciding what to lift and attribute, not just what to rank. It also spreads across multiple engines with their own behaviors, rather than optimizing for one dominant search algorithm.
How does measurement change?
SEO measures rankings, impressions, and clicks. GEO measures share-of-answer: whether and how each engine cites you for your target questions. A page can be cited heavily by AI while sitting on page two of traditional search, so the old dashboards don't capture the new win — you need to track citations directly.
Should I stop doing SEO?
No. Search still drives real traffic, and much of what you do for it compounds into GEO. Treat GEO as an additional, increasingly important layer on top of solid SEO — not a replacement, and not an afterthought.
The short version
SEO wins clicks from a list; GEO wins citations inside answers. Same foundations, different goal and metric. Keep your SEO, add GEO, and measure the new game on its own terms.