A watermark may refer to any of the following:
1. A watermark is a logo or text superimposed on an image to help prevent an image from being copied or allow others to know where it was copied from and who owns the rights. The picture shows an example of such a watermark.
2. An image that has a fixed location and does not move along with other content. Watermarks are often used on web pages so that the site's logo or banner is always visible in the background.