Digital Watermarking is the process of embedding information in a digital file such as an image, video or audio file. There are mainly two types of digital watermarks: Visible watermarks and invisible watermarks.

In a visible watermark, the information can be clearly seen by the user as embedding a small copyright text or a logo image in an image or as writing a message into a video. In an audio file, a visible watermark can be an addition recording on the audio. Programs such as WatermarkIt can write digital watermarks on images and photos.
In invisible watermarks, information is embedded in such a way that the viewer cannot see the information. The information is hidden without modifying the actual digital file. This can be used in order to prove copyright or ownership issues of an image, video or audio file.