This article appears in the Oxford Handbook of Sound and Image in Digital Media edited by Carol Vernallis, Amy Herzog, and John Richardson. The essay presents the theoretical analysis of key conceptual steps involved in generating visualizations of media artifacts and large collections of these artifacts. These steps and associated concepts are “data,” “metadata,” “feature extraction,” “information visualization,” “media visualization,” “mapping” and “remapping.” The essay first briefly reviews recent developments in visualization techniques. Next, it discusses the key conceptual steps that take us from artifacts to visualizations. As illustrations, the essay uses selected visualizations created in the author’s lab softarestudies.com. The last section summarizes the discussion and links the new possibilities opened up by use of visualization of large visual collections to the relevant concepts developed by earlier twentieth-century art historians—Heinrich Wölfflin’s “Art History Names” and André Malraux’s “Museum without Walls.”