Glossary

Query node - one of the Joystream services responsible for processing event data from the Joystream blockchain into higher level abstractions (entities), like e.g. Membership, Video or CouncilElections, which can then be easily queried via a rich GraphQL API it provides. It was built using a framework called Hydra (inspired by Ethereum's The Graph), which was later developed into Squid SDK. It's open-source and available on GitHub.

Orion - backend node for Joystream gateways, such as e.g. Gleev.xyz. It consists of Subsquid block processor, GraphQL API and Authentication API. Orion is open-source and available on GitHub.

Metaprotocol - in context of Joystream, metaprotocol is a set of messages defined with Protocol Buffers that can be serialized and included as extrinsic arguments, even though the Joystream runtime doesn't understand /parse them (instead, they are parsed by event processors, such as those inside Query Node or Orion). The library containing the definitions of currently supported metaprotocol messages is @joystream/metadata-protobuf.