Open-weights model
An AI model whose trained numbers, called weights, are published so anyone can download it and run it on their own computer or server.
A trained model is essentially a very large set of numbers, known as weights. Some companies keep their weights private and let you use the model only through their website or app. Others publish the weights so people can download the model, run it themselves and adapt it.
A small business might download an open-weights model and run it on its own server, so customer documents never leave the building. Researchers use these models to study how AI works.
"Open weights" is not quite the same as "open source". Often the weights are shared but the training data and full method are not, and the licence may limit how you can use the model. Check the licence before relying on one. Publishing weights also means safety rules can be removed by others, which is part of a lively debate.
Related: Model (AI model), Fine-tuning, Large language model (LLM)