Nowadays, digital video data is increasingly available for public accesses. However, the rate at which access to this key element of multimedia computing is growing is unparalleled with the tools and techniques that have been developed for retrieving and browsing the media. In recent years, a lot of research efforts have been put into video data management, amongst other active research topics, video data modeling has been extensively researched, but virtually no work has been done in the area of video data modeling that reveals the role of metadata in enhancing video retrieval systems, and only little work has been done in the area of video data repository modeling. In many cases the motivation of many of the research efforts has been the accessibility problem. In this book, a holistic video data model with two separate representation schemes is proposed. It distinguishes three blocks: the frame-based block, the object-based block and the external description block. Moreover, a video data repository model as well as the accompanying similarity-based video retrieval techniques that can be conveniently used under OR-DBMSs environment are also proposed.