LLMs are the foundation of modern AI search. They learn from billions of text data points to understand language, generate responses, and provide recommendations.
For AEO, understanding how LLMs work is crucial: LLM knowledge comes from training data — i.e., publicly available internet content. If your brand is frequently mentioned on high-quality websites, LLMs are more likely to recommend you.
Major LLMs include OpenAI's GPT series (powering ChatGPT), Google's Gemini, Anthropic's Claude, and Meta's Llama. Each LLM has different training data and recommendation logic, so effective AEO requires cross-model optimization.