All metadata in GMA needs to be modelled using [Pegasus schema (PDSC)](https://linkedin.github.io/rest.li/DATA-Data-Schema-and-Templates) which is the data schema for [rest.li](https://rest.li).
Conceptually we’re modelling metadata as a hybrid graph of nodes ([entities](../what/entity.md)) and edges ([relationships](../what/relationship.md)), with additional documents ([metadata aspects](../what/aspect.md)) attached to each node.
Below is an an example graph consisting of 3 types of entities (User, Group, Dataset), 3 types of relationships (OwnedBy, HasAdmin, HasMember), and 3 types of metadata aspects (Ownership, Profile, and Membership).
