Aave protocol subgraphs are hosted on the Graph Protocol Network and use a standardized GraphQL API endpoint to query indexed information from Aave smart contracts.  Using the Aave Subgraphs, developers can track on-chain activities like borrows, deposits, collateral ratios, and more. These insights are useful for building decentralized applications that analyze and report on individual or market-level activities. Additionally, developers can efficiently extract necessary information without thoroughly investigating the internal protocol implementation.