Surrogate Files

This term is now losing favour to Proxy files. Surrogate files are those derived from an original digital asset and are typically used in combination with metadata to help users locate media prior to downloading them. They usually provide a preview in the form of a thumbnail, smaller image, preview clip or other file that can be transferred quickly. In some cases, surrogate files may be the actual file supplied, for example, if an image is to be used in a PowerPoint presentation and the user does not have a graphics program installed. Surrogate files are sometimes referred to as Derivative Files. Also see watermarking for information on how surrogate files can be used to enforce copyright.