Context window

The amount of text (measured in units called tokens, roughly corresponding to word fragments) a large language model can consider at once when generating a response, including both the current prompt and any conversation history provided. A model with a larger context window can work with longer documents or longer conversations in a single exchange without losing track of earlier content.

The maximum amount of text a model can consider at once, covering the system prompt, the conversation history, any retrieved passages, and the user's question together. When the material you want to supply exceeds the window, something must be dropped or summarized, which is itself a configuration decision about what the model gets to see.

The portion of a conversation's text that a language model is actively given to read before generating its next response, which is how the tool appears to "remember" earlier details within a single ongoing conversation, even though it has no independent memory of that conversation once it ends.

The maximum amount of text an AI model can consider at once. Claude's standard context window is about 200,000 tokens (roughly 150,000 words); a 1,000,000-token window is available on newer Claude models for higher usage tiers. Gemini Pro models offer 1,000,000+ tokens.

the finite amount of text a model can consider at once when producing a single response, including the current conversation and anything retrieved into it; distinct from memory, which is the mechanism deciding what fills that window.