Before I start going into more depth on data dependencies and mutations, I think it makes sense for me to throw some general Relay and GraphQL terminology definitions out there:

• Relay: A library that manages application data fetching and data mutations and provides higher-order components that feed data into our application components
• GraphQL: A query language used to specify data requirements and data mutations
• Data dependency: An abstract concept that says a given React component depends on particular data
• Query: A query is the part of a data dependency, expressed in GraphQL syntax and executed by an encapsulated Relay mechanism
• Fragment: A part of a larger GraphQL query
• Container: A Relay React component that passes ...