Model

Model generally refers to the large, trained file that the AI interface is using to run diffusion. In most situations, you can only be using one model at a time, unlike things like LoRAs, LyCORIS, Embeddings, or other things that modify the weights of the currently loaded model.

There are several file types for models that you may run into. As AI is still developing rapidly, new technologies are added all the time. Some of the below file types are remnants of our first steps, and what is the most popular at the moment may be replaced with a new one at any time.

type	extention	notes	popularity
Safetensor	.safetensor	Created to patch the security hole in .ckpt, can't execute code.	currently most popular model type on Civitai.
Checkpoint	.ckpt	A "one file" version of a diffusion model, criticized for potential code vulnerability (potential to execute code if maliciously modified after creation).	These show in the Civitai download as PickleTensor files. Somewhat distrusted, most people prefer safetensor
diffusion	(folder of files)	Oldest of the model types listed here, diffusers have a folder structure with multiple files that make up the entire model.	Not available through Civitai, but often show up on Hugging Face.

See Checkpoint