I've found some advice for setting up tagging systems in relational and document databases, but nothing for graph/multi-model databases. I am trying to set up a tagging system for documents (let's...

Someone could explain how a document database works as a graph database also? What is the difference between ArangoDB and Neo4j?

I am looking to dip my hands into the world of Multi-Model DBMS, I have no particular use cases, just want to start learning. I find that there are two prominent ones - OrientDB vs ArangoDB, but w...