> For the complete documentation index, see [llms.txt](https://docs.u2u.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.u2u.xyz/services/the-graph.md).

# The Graph

### What is The Graph?

The Graph is a decentralized protocol for indexing and querying blockchain data. The Graph makes it possible to query data that is difficult to query directly.

### What is Graph Node?

Graph Node is the component which indexes subgraphs, and makes the resulting data available to query via a GraphQL API. As such it is central to the indexer stack, and correct operation of Graph Node is crucial to running a successful indexer.

### What is Subgraph?

A subgraph extracts data from a blockchain, processing it and storing it so that it can be easily queried via GraphQL.