A Context Window is the span of text or tokens that a large language model (LLM) can process, remember, and reason over at one time. It defines the model’s short-term memory—everything inside the window is visible to the model during a single response or conversation, while anything outside it is effectively forgotten. In AI Search Optimization, understanding context windows is critical because it influences how much of a brand’s content, schema, or surrounding context an AI can interpret before generating an answer. Expanding or optimizing what fits within the context window—through concise, semantically rich structuring—improves the likelihood that key brand facts and signals are retained and cited.