At the starting point of this thesis stands the hypothesis that the description and analysis ofephemeral, variable and performative works of art, such as net-art, calls for a methodologicaladjustment. Existing models of art-historical description and terminology, which primarilycover static and physical objects in painting, architecture and sculpture, are inadequate for thetreatment of digital art and require an adaptation.In net-art, work, image and source form a unit: on the phenomenological level, no distinctionbetween these separate conditions can be made. The production and representation of thework takes place in its own media. The limitations of the applicability of established arthistoricalmethods are especially evident in regards to questions of materiality andauthenticity: digital works are temporary, variable and participatory. Hence, the focus isshifting from the description of physical objects to the recording of processual operations.A central role in the formulation of a specific terminology is assigned to the field ofmetadating. Because of the performativity of works of net-art and the aforementioned medialunity, this sub-genre of media art requires not only a specific descriptive terminology, but alsoa distinctly different way of metadating than is practiced in the visual arts. The methodologyof work-description shares a symbiotic relationship with the process of metadating: While atfirst, metadata is itself drawn from the description of a work, it in turn serves to provide astrictly formalized catalogue for description.Only through the use of suitable metadata standards and the application of adequateterminology, digital and especially net-based works of art can be fully exploited as validscientific sources in art-historical research and teaching.