Open weights
A model whose trained files are published for anyone to download and run on their own hardware.
What it tells you about a developer
Open-weight work means the developer has served a model themselves: choosing hardware, watching speed and cost, and keeping it running. Teams in health, finance, and defense reach for open weights because their data cannot leave their network.
The weights are the numbers a model learned during training, and they are what makes it work. A lab that publishes them lets anyone run the model on their own computers, adjust it, and use it without sending data to an outside company. Llama is the best-known example. Labs that keep their weights private sell access through an API instead.