[haadcode]

To clarify here, OrbitDB's core is an append-only, immutable log CRDT. While a mouthful, what is gives, is a distributed (decentralized) database operations log. Almost any type of database, or data structure, can be then built on top of that log. The log in OrbitDB is a Merkle-DAG [1], so, a graph.

Key-Value databases, feeds, and other data model types that OrbitDB supports by default, are all built on that log. You can also create your custom database types, ie. custom data models.

[1] https://discuss.ipfs.io/t/what-is-a-merkle-dag/386/4

[haadcode]

The log described above is this https://github.com/orbitdb/ipfs-log

[sagichmal]

What makes it a CRDT?

[haadcode]

Posted this in another reply above, but give this a read: "Merkle CRDTs" (https://arxiv.org/abs/2004.00107).