The negative prompt is a parameter that tells Stable Diffusion what you don't want to see in the generated images. When specified, it guides the generation process not to include things in the image according to a given text.

A negative prompt may prevent generating specific things, styles, fix some image abnormalities, and greatly improve the quality. Let's look at examples comparing the same images with and without negative prompts:

Improving the overall quality and body proportions while creating  'portraits':

Without negative prompt

Negative prompt: 'Disfigured, cartoon, blurry, nude'

Removing visual features e.g. 'moss' from the 'forest':

Without negative prompt

Negative prompt: 'moss'

Changing the image lighting and making it look sharper by removing fog:

Without negative prompt

Negative prompt: 'darkness, fog'

We hope our guide helped you understand the negative prompts parameter in Stable Diffusion, and you'll use what you've learned to generate even better art.