What is Context Window?
The amount of text a model can 'remember' within a single conversation.
// Explanation
The context window is the model's working memory — everything it can read and consider at any given time. If your conversation exceeds that limit, the model literally forgets what you said at the beginning. Modern models have windows of 128K, 200K, or even 1 million tokens, equivalent to several complete books.
// Example
If you paste an entire novel into Claude with a 200K token window, it can read the whole thing. If you paste two long novels into a model with 32K, it'll start 'forgetting' the beginning.