Foundation Model
Definition
A large, generally pre-trained AI model that is fine-tuned or adapted via prompts as the basis for a variety of downstream applications. The term covers language models, multimodal models and domain-specific pre-training; it is broader than "large language model".
Noise — Signal
"Foundation model" and "LLM" are used synonymously, but they are not the same — every LLM is a foundation model, but not the other way around. More important in the boardroom is the legal dimension: in the EU AI Act, "general-purpose AI model" has a very specific meaning with thresholds above which transparency, documentation and risk-management obligations kick in — also for companies that deploy such a model without training it themselves. Anyone who buys, integrates or further develops foundation models is not automatically only a "user".
The right question
Not: "Which foundation model are we deploying?" But: "In which role do we appear — user, deployer, provider, modifier — and which AI Act obligations follow if we fine-tune the model or enrich it with our own data?"