Each Bitcoin is made up of small units called satoshis, much like how cents make up dollars. As introduced by the Ordinal Theory Handbook, individual satoshis can be inscribed with content, such as images or text, to create unique Bitcoin-native digital artifacts that can be held in Bitcoin wallets and transferred using Bitcoin transactions. Inscriptions are as durable, immutable, secure, and decentralized as Bitcoin itself. (information via gamma.io)