The Graph (GRT) is an Ethereum token that powers The Graph, a decentralized protocol for indexing and querying data from blockchains. Just as Google indexes the web, The Graph indexes blockchain data from networks like Ethereum and Filecoin. This data is grouped into open APIs called subgraphs that anyone can query.
Our view: The Graph Protocol will eventually be the “Google” of the blockchain ecosystem. This is a scalable method of enabling search across any component of the Bitcoin and Ethereum ecosystems, and does so in a way that aligns human action to maintain a trusted fabric enabling quality in search results.
For more see: Official website