01 · The Big Picture
Open vs Closed Weights
Downloadable, or API-only
Whether a model provider releases the trained weights. Open-weight models can usually be downloaded and run under their license; closed-weight models are served by the provider. Open-weight does not automatically mean open-source, unrestricted, private, or safe.
Concrete example
A team may run an open-weight model on its own hardware, while using a closed model through an API for another task.
Why it matters
Drives the core build-vs-rent decision — control and privacy versus convenience and peak capability.