Ordinals and inscriptions are technologies for creating non-fungibility on bitcoin.
Ordinals on the bitcoin blockchain is an open-source project which uses a satoshi (or "sat," the smallest unit of a bitcoin) ordering scheme, and an index which communicates with a bitcoin node to track the location of all satoshis. Using this scheme, one can track and transfer individual sats. One can also use the ordinals standard to prove ownership of specific parts of the blockchain.
Ordinals are a way to put a numerical order on individual sats.
The BIP (bitcoin improvement proposal) for ordinals contains more technical details of the way in which satoshis are ordered and numbered.
Inscriptions on the bitcoin blockchain describes art or other images that have been added directly to the blockchain. Inscriptions are tied to a specific ordinal sat. Because sats can be owned and moved by individual people, the ordinal sat is a method of tying ownership of the image on the blockchain to a specific individual.
Inscriptions have been compared to NFT (non-fungible token) art on ethereum, but the method of inscribing, securing, and moving ownership of the inscription is different than NFTs, which use the native token function.
How do images get on a blockchain?
A blockchain is a public database that is distributed among many computers all around the world. Almost any type of data can be added to this database.
Since images are just data, the data from the images can be included in specific bitcoin blocks. Since that data is stored in specific blocks, it's possible to take a specific sat, which is part of the transaction data, and assign it to a particular wallet address. And since wallet addresses are owned by individuals, one can "own" the inscription on the blockchain by owning the specific ordinal sat associated with the image.
Individual satoshis can be inscribed with such content, creating unique bitcoin-native digital artifacts that can be held in bitcoin wallets and transferred using bitcoin transactions. Inscriptions are durable, immutable, secure, and decentralized - just like bitcoin itself.
Why would I use inscriptions?
Inscriptions can be useful for collecting and trading unique digital artifacts. The ordinal system allows digital artifacts tied to ordinal satoshis to be individually tracked and traded as curios, which may or may not have numismatic value as a collectible.
Ready to get started? Check out Setting up your Casa vault for ordinals and inscriptions.
If you already have a Casa vault set up, see How to secure and send bitcoin ordinals and inscriptions.
You can also check out the Ordinal theory handbook for a deeper dive down the rabbit hole.
Ready to get started with Casa and ordinals? Become a Casa member to get peace of mind for your digital wealth today.