Visual media are sources of data or information in the form of visual representations. These may be abstractions, analogues, rough illustrations, or digital reproductions of the objects the data pertains to; as such they generally require the interpretation of the data gatherer. Their level of reliability compared to other sources varies considerably.

These sources may be hosted on the internet, printed in publications, displayed through broadcast media, or otherwise disseminated. They are generally available or at least citable as stable and traceable future references.

The information is obtained from a representation, so its usefulness depends on what the image actually depicts and how it was produced. Hosting a photograph or drawing on a website does not turn the represented evidence into ordinary webpage text.