This article provides an overview of the tools specified by the MPEG-7 standard for describing the structure of multimedia content. In particular, it focuses on tools that represent segments resulting from a spatial and/or temporal partitioning of multimedia content. The segments are described in terms of their decomposition and the general relations among them as well as attributes or features of segments. Decomposition efficiently represents segment hierarchies and can be used to create tables of contents or indexes. More general graph representations are handled by the various standard spatial and temporal relations. A segment can be described by a large number of features ranging from those targeting the life cycle of the content (e.g., creation and usage) to those addressing signal characteristics such as audio, color, shape, or motion properties.