Glossary

Diffusion

Short answer

How image models work: building an image by progressively removing random noise.

Diffusion models learn during training by adding noise to images step by step and learning to reverse that process. At generation time they start from pure noise and progressively remove it, guided by the prompt, until the image emerges.

This method is why the same prompt gives a different result each time: the starting noise is random. The value that fixes that randomness is the seed.

The step count determines how many stages the denoising takes. Too few steps gives a blurry image; too many gives slow generation with no added benefit.