Ordinal theory is a new method of inscribing data onto the Bitcoin blockchain, endowing the smallest unit of Bitcoin, the satoshi (sat), with numismatic value, and allowing for the tracking, trading, and transferring of individual sats. It uses different representation methods to enumerate satoshis and describes their rarity based on their position in the blockchain. Inscriptions are a way of recording arbitrary data within a Bitcoin transaction, embedding data onto the Bitcoin blockchain through a two-step transaction process. It has the potential to impact the Bitcoin and cryptocurrency industry in the medium to long term but has also sparked divisions within the community. Inscriptions are also influencing the NFT space, as seen with protocols like Nervos' Omiga and Spore.