Claude works by sequence prediction
Claude is a conversational assistant, based on a large language model (LLM). The model uses all the text that you have sent it (your prompt) and all the text it has generated so far to predict the next token that would be most helpful.
This means that Claude constructs its responses one set of characters at a time, in order. It cannot go back and edit its response after it has written it unless you give it a chance to do so in a subsequent prompt.
Claude can also only see (and make predictions on) what is in its context window. It can’t remember previous conversations unless you put them in the prompt, and it can’t open links.
Prompt length
The maximum prompt length that Claude can see is its context window. See our model comparison table for a list of context window sizes per model.