principles.fyi · the brain · concept

foundation model

One big pretrained model that many different applications get built on top of.

one pretrained base -> many apps (chat, search, coding, ...)

A foundation model is a single large model — pretrained once on broad data — that serves as a shared base for many downstream uses, via prompting or fine-tuning. The name (coined at Stanford in 2021) captures the shift from training a fresh model per task to building one general model and adapting it everywhere. Because so much depends on that one base, the choices baked into its pretraining data (what's included, what's filtered out) ripple out to every application built on it.