Initially we just had documents on our own desktop, then on a file server for sharing with others. After that we wanted to add additional information (tags) about the document when moving towards Document Management. Then we noted that we have a much broader range of content that we want to manage and arrange when we progressed towards Content Management.
The latest step is Dossier Management where all relevant and related content is managed as a dossier in one simple page where it is exceptionally easy to store and retrieve files in the dossier.