Active Indexers, Curators and Delegators can earn income from the network proportional to the amount of work they perform and their GRT stake.

Curators are subgraph developers, data consumers or community members who signal to Indexers which APIs should be indexed by The Graph Network. Curators deposit GRT into a bonding curve to signal on a specific subgraph and earn a portion of query fees for the subgraphs they signal on; incentivizing the highest quality data sources. Curators will curate on subgraphs and deposit GRT via the Graph Explorer dApp. Because this occurs on a bonding curve, that means that the earlier you signal on a subgraph, the greater share of the query fees you earn on that subgraph for a given amount of GRT deposited. This also means that when you go to withdraw, you could end up with more or less GRT than you started with.

In graph theory, a tree is a connected acyclic graph; unless stated otherwise, in graph theory trees and graphs are assumed undirected. There is no one-to-one correspondence between such trees and trees as data structure.

Ruby has some really nice libraries for working with linked data. These libraries allow you to work with the data in both a graph and resource-oriented fashion, allowing a developer to use the techniques that best suit his or her use cases and skills.