Glossary · Phase 1 · Building with LLMs
Closed model
A model you can only use through its maker's API: you can't download its weights or run it yourself.
Try it now
Using the prices in this lesson. Output costs five times as much as input, so watch how much the output slider moves the total.
Learn it properly
Choosing a model · Trade capability, speed and cost across model families. About 25 minutes.
Other terms from the same lesson
- fine-tuning: Further training a pretrained model on a smaller, focused set of examples to change its behavior.
- open-weight model: A model whose weights are published, so you can download and run it yourself.
Never trained an AI?
Teach a small one to write, right in your browser. It takes about 20 seconds and needs no account.