Digital Rights Management (DRM) is an issue of controlling and managing digital rights over intellectual property. It has recently broadened its scope from being merely a content protection concern to description, identification, trading, protection, monitoring and tracking of rights over tangible or intangible assets. In our study we found out an essential problem of the domain: lack of models on an appropriate level of abstraction needed to support research and system development. Modelling, identifying and describing the core entities enable the rights management functionalities. This chapter contributes in recognizing the principal entities and providing detailed description on current identification and description matters and solutions. Our analysis results in the remark of distinguishing the evolution stages of digital content and separating the different offers and agreements through which the rights are traded between the value chain participants. Based on the depiction of the domain model, this chapter additionally gives insight into the future trends and issues on the DRM domain.