A seed value is a number that relates to the starting point of the AI image generation process inside the model. For example, if you generate an image with the same prompt twice the two images will likely be very different because a new seed is used each time.

If you generate an image and like it, and want to generate a very similar image that's slightly different, you might change your prompt and input the seed value from the previous image. This will result in a very similar image but with the changes in the prompt.

To view and copy the seed from a particular image, click the three dots in the top right corner of the image and select 'View Provenance':

You can copy the seed from the image you like here and then paste it beneath the prompt in 'Generate Options'

Note: Currently seed values are only populated when you generate one image at a time, and they are only supported by the following models: