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

# Glossary

> Definitions for the core deCDN terms — bao verified streaming, blobs, capacity bonds, payment channels, vouchers, probes, nodes, and clients.

| Term                   | Definition                                                                                                                                                                                                                                                                    |
| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Bao**                | The BLAKE3 verified-streaming encoding used for all delivery. Interleaves content with hash proofs so any requested range verifies against the root once aligned to its enclosing 16 KiB chunk-group boundary.                                                                |
| **Blob**               | A content-addressed byte sequence. Every blob is identified by its hash; clients verify received bytes against the known hash.                                                                                                                                                |
| **Bond (capacity)**    | TOKEN locked in `CapacityBond` proportional to a node's declared bandwidth (`bond = k × Mbps^α`) — the only TOKEN-side requirement to join the mesh; the bond scales with declared capacity rather than a flat minimum. Returned on deregistration after an unbonding period. |
| **Channel (payment)**  | On-chain escrow between client and node that backs off-chain vouchers. Opens with a deposit; settles with the highest-nonce voucher after a dispute window.                                                                                                                   |
| **Client**             | A lightweight QUIC endpoint that streams content and pays per MB. No stake, no gossip publish.                                                                                                                                                                                |
| **DHT**                | Kademlia-subset content discovery. Nodes self-publish records when caching a blob.                                                                                                                                                                                            |
| **Full holder**        | A node caching a complete blob (as opposed to a partial range). Only full holders are eligible as sources for a multi-source fetch.                                                                                                                                           |
| **Gossip**             | Epidemic broadcast over topic channels for node metadata and rate updates.                                                                                                                                                                                                    |
| **Hash sequence**      | An ordered collection of blob hashes (a directory or manifest equivalent).                                                                                                                                                                                                    |
| **Multi-source fetch** | Fetching one large blob from several full holders in parallel, each serving bao-aligned work units, up to a configurable maximum (`max_sources`). Each source is an ordinary paid stream — no new wire protocol.                                                              |
| **Node**               | A bonded QUIC endpoint that caches and delivers blobs. Some are origin-backed; others are pure caches.                                                                                                                                                                        |
| **Origin-backed node** | A node configured with an S3-compatible store, NFS mount, or local disk — the canonical source for specific blobs. Never experiences a true cache miss.                                                                                                                       |
| **Origin backend**     | The opaque storage behind an origin-backed node (S3, R2, B2, MinIO, NFS, local disk). Never exposed to the network.                                                                                                                                                           |
| **Outboard**           | A blob's BLAKE3 hash tree, stored separately from its content. An origin-cold node must import or build the outboard before it can serve verified ranges.                                                                                                                     |
| **Peer mesh**          | The flat set of all bonded nodes. Discovery via gossip; content location via DHT.                                                                                                                                                                                             |
| **Probe**              | Parallel latency + availability check that runs before any delivery commitment.                                                                                                                                                                                               |
| **Selection score**    | A combined ranking over advertised price, observed latency, and reputation. Lower is better.                                                                                                                                                                                  |
| **TOKEN**              | The deCDN bonding/governance token: locked as a node's capacity bond and burned by the buyback sink. Not used for payments; governance weight comes from delivered bytes, not TOKEN balance.                                                                                  |
| **USDC**               | The payment currency for all delivery. Fixed at deployment; channels deposit, voucher, and settle in USDC.                                                                                                                                                                    |
| **Voucher**            | A signed off-chain payment message. The primary payment instrument between client and node.                                                                                                                                                                                   |
| **Work unit**          | A bao-aligned byte range assigned to a single source during a multi-source fetch. Independently verifiable, so it can be re-dispatched or hedged without re-reading from the start.                                                                                           |