This chapter introduces the reader to the key role that metadata can play for managing various digital media, often also called new media, such as image, audio, and video in information systems. We present different views on how metadata can be modeled, classified, extracted, managed, and applied, to support a convenient handling of digital media. We discuss various issues on the role of metadata from different viewpoints: the application scenario perspective, the media processing perspective, and the metadata type and classification perspective. We also look at the world of standards for handling metadata.

Finally, the chapter gives an outline of the book and provides a coherent view over all the chapters. Each of the chapters in the book and its main issue in the field is introduced in brief with respect to the concepts and issues discussed in this paper.