The whitelist determines what websites may embed your image. Websites in your global whitelist have the ability to embed any image of yours. Use this for your own websites or others that have your permission. You can edit the global whitelist in your account settings.

If you want to control access on an image by image basis, you can edit the whitelist for an individual image in the image editor. Note that this will not replace the global whitelist. The two lists will be merged.