---
type: Section
title: Terminology
---

# Terminology

- **Knowledge Bundle** (or **bundle**): a self‑contained, hierarchical collection of knowledge documents.
- **Concept**: a single unit of knowledge represented as one markdown document.
- **Concept ID**: the file path of the concept within the bundle, without the `.md` suffix.
- **Frontmatter**: a YAML metadata block at the top of a markdown file.
- **Body**: the markdown content following the frontmatter.
- **Link**: a standard markdown link used to express relationships between concepts.
- **Source**: a material a concept derives from, recorded in the `sources` frontmatter field.
- **Provenance**: the set of sources a concept derives from.
- **Credibility signal**: objective per‑source facts (author, usage_count, last_modified).
- **Actor**: identifier of who performed an action, using the convention `<producer>/<version>`, `human:<id>`, or `process:<id>`.
- **Trust tier**: level derived from the `verified` field (unverified, machine‑confirmed, human‑reviewed).
- **Attested Computation**: a concept (`type: Attested Computation`) that carries a sanctioned way to compute a value.
- **Executor**: runs a computation and returns a receipt.
- **Receipt**: evidence returned by an executor, inspected by an attester.
- **Attester**: deterministic code that validates a receipt.