Glossary
Ordinals
A 2023 Bitcoin protocol for numbering individual satoshis and "inscribing" arbitrary data onto them, enabling NFT-like artifacts on Bitcoin.
Ordinals, introduced by Casey Rodarmor in January 2023, assigns a sequential number ("ordinal") to every satoshi based on the order in which it was mined. Inscriptions attach arbitrary data — typically images or text — to a specific satoshi, leveraging the witness data made cheap by Taproot.
The result is a native Bitcoin NFT-like artifact, no L2 needed. Ordinals briefly drove Bitcoin fees to multi-year highs in 2023 and created the entire BRC-20 token standard ecosystem on top of the same inscription infrastructure.