Answer

Context Window: How Much an AI Can Remember at Once

A context window is how much text an AI can read and remember during one conversation. Think of it like a whiteboard — the AI can only see what fits on that whiteboard. If your conversation gets too long, older parts slide off the edge and the AI forgets them. A bigger context window means the AI can hold more in its head at once — longer documents, longer chats, more details. When the window fills up, the AI does not know what it cannot see anymore, and that causes mistakes.

Example: You paste a 50-page contract into an AI with a small context window. It reads the beginning, forgets the middle, and gives you wrong answers about clauses it never actually saw.