Model architecture
Open-weight model
What is open-weight model?
An open-weight model has downloadable parameters, so it can be run, fine-tuned and deployed by anyone under its licence. It is distinct from open source: the weights are available, but the training data and code usually are not.
The distinction is not pedantic. An open-weight model under a community licence may carry use restrictions, naming requirements and revenue thresholds that a genuinely open-source licence would not.
A small number of families go further and publish the training data, the code and the intermediate checkpoints. That is the level at which a claim about what a model was trained on can actually be verified.
Related terms
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