Foundation vs. Instruct vs. Chat Models: One Question, Three Answers (opens in new tab)

A hands-on tutorial you can run for free in Google Colab. Run it yourself: open foundation_instruct_chat_tutorial.ipynb in Google Colab and run every cell top to bottom. It uses the SmolLM2-135M family — small enough for a free CPU runtime, no GPU needed. Why this confuses everyone People say "LLM," "GPT," "an AI model," and "ChatGPT" as if they were the same thing. They aren't. There's a ladder of training stages between "a model that read the internet" and "an assistant you can chat with," ...