A large language model (LLM) is a type of AI model trained on vast text corpora to understand and generate natural language. LLMs power AI search tools such as ChatGPT, Claude, and Gemini — processing queries, retrieving content, and synthesizing responses at scale.
LLMs are the engines of AI search. Understanding how they work — training data, weights, retrieval, context windows — explains why AI SEO behaves differently from traditional SEO. A brand that understands LLM architecture can make better decisions about where to invest: training corpus presence for parametric knowledge, structured data for retrieval accuracy, and content structure for context window extraction.