tghw's interpretation is closer to being correct.
A Veracity repo can have lots of DAGs (directed acyclic graphs).
A DAG in a repo can either be a "tree dag" or a "database dag".
Veracity's notion of a "database" is a model that is unique to Veracity, although its concepts are quite common. Records. Fields. Multiple record types. Simple constraints. Links between records. Simple queries. It's not SQL.
Nothing here implies that Veracity will help you, as a database developer on SQL Server or Oracle, manage the versioning of your schema and sprocs and so on. Those are interesting features, but they're distinct from (and a lot higher level than) the stuff I was describing.