Context Window Explained: Why AI Forgets

The Context Window

Every model has a maximum number of tokens it can handle at once. This limit is called the context window. It covers everything in the request: your instructions, the conversation so far, any pasted documents, and the reply the model is writing.

If a long chat goes past the window, older messages have to be dropped or summarized. That is why a model can "forget" something you said much earlier.

Bigger windows let you include more material, but they do not make the model read it more carefully.