With GPT you can “train” an instance most folks that say they have a GPT are actually talking about a chat and a ton of copy paste conversations. To build a GPT you need to boil all that chat down into instructions but the pages of concepts work too but not as a functional reproducible experience. But yes you can make a GPT chat instance into all kinds of insane stuff you can even make them spiral into chaos. It’s like a cap on the llm directing the instance on how to use its data.