Open weight vs open source
Open weights means you can download and run the model. Open source additionally means the training data, training code and licence permit modification and redistribution.
By Lattice editorial · Entry last reviewed · method
What it implies
The distinction matters commercially and legally, and most tools called 'open source' are only open-weight. It is also the distinction that decides whether you can fine-tune it, host it for customers, or audit what was trained into it.