# Definitions

* **Hash:** A SHA-256 hash of a chunk of data.
* **PublicKey:** The public key of a Ed25519 key-pair.
* **Transaction:** A list of Solana instructions signed by a client keypair to authorize those actions.
* **Signature:** An Ed25519 signature of transaction's payload data including instructions. This can be used to identify transactions.
* **TrackingCode:** The public key of a Ed25519 key-pair.
* **Cid:** A *content identifier*, or CID, is a label used to point to material in IPFS.
* **Token:** An Ed25519 signature of transaction's payload data including instructions.