one sentence answer
Token is the unit used to calculate length when the model reads and generates content. It is not exactly equal to the number of Chinese characters or English words, but the fragments after the text is segmented inside the model.
Why should we understand Token?
it affects the length limit
When you post too much data, the model may not be able to process it all at once because it exceeds the context window.
it affects cost
Many APIs or advanced tools bill based on input and output tokens.
it affects speed
The longer the data, the more time the model usually needs to process.
Practical understanding
Ordinary users do not need to accurately calculate tokens. All you need to know is that long files, long chat records, multiple rounds of conversations and large amounts of output will all occupy tokens.
Usage suggestions
When processing long data, let AI summarize it segment by segment, and then combine the summaries for analysis. This is usually more stable than cramming everything in at once.
continue learning
Token and context window are looked at together: token is the unit, and context window is how many units can be loaded at one time.