Metadata play an essential role in making a digital object discoverable, accessible, usable, and interpretable. By adopting the conflation of data and metadata in the expression (meta)data modelling, the key aim of the contribution is to properly highlight the multi-layer dimension of the descriptive representation levels informed by a digital object, showing how this constitutes the foundational basis on which a (meta)data model is grounded. The contribution offers insights into the essential principles of shaping a (meta)data model, their applicability and interoperability challenges, with the aim to serve as an entry point for anyone interested in the field looking for good practices.