> ## Documentation Index
> Fetch the complete documentation index at: https://docs.herodotus.cloud/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> Core HDP terms

* **Dry run**: Simulation phase that discovers which on-chain keys are needed. See [Pipeline stages](/data-processor/pipeline).
* **Fetcher**: Stage that collects cryptographic proofs for discovered keys. See [Pipeline stages](/data-processor/pipeline).
* **Sound run**: Offline verification and execution stage. See [Pipeline stages](/data-processor/pipeline).
* **Memorizer**: Cairo0 dictionary-based storage for verified data. See [State management](/data-processor/state-management).
* **MMR**: Merkle Mountain Range accumulator for block headers. See [Verification model](/data-processor/verification).
* **MPT**: Merkle Patricia Trie used for Ethereum state proofs. See [Verification model](/data-processor/verification).
* **Task hash**: Unique identifier for a computation. See [Output model](/data-processor/output).
* **Output root**: Merkle root of computed results. See [Output model](/data-processor/output).
* **Injected state**: Custom persistent state backed by a Patricia trie. See [State management](/data-processor/state-management) and [State Server](/data-processor/state-server).
* **Unconstrained data**: Data validated by hash instead of inclusion proof.
* **STWO**: STARK proving path supported by HDP tooling. See [Proving with STWO](/data-processor/proving).
* **Bootloader**: Cairo0 program that executes compiled Cairo1 modules.