GraphQL is the link between the blockchain data and the application a user wants to feed it to. Finally, after the whole process, users can view the results of their query from within their applications.

Basically, this is how the cycle of data query and indexing works in the platform. Users can refer to Graph Explorer to browse the subgraphs that already exist in the platform. Each of these subgraphs has a playground where users can perform queries using GraphQL.