Within cooperative Information System (IS), Educational Engineering scientific community agrees that Information must be organised and structured using ontologies that the developers can manage with meta-data. So, we propose some UML based models and a specific metadata structure dedicated to Educational IS. In this paper we present a Net-Learning case study, a conceptual model of Educational IS and we describe the main characteristics of such an IS. This case study is representative of collaborative learning notions. Model, or rather models, take into account the static and dynamic aspects necessary for the description of learning processes: we formalize them with the UML language. Finally, we detail the structural aspects of this IS.