Satoshi

Satoshis, often abbreviated to “sats”, are the atomic unit of Bitcoin, named after Bitcoin’s creator, Satoshi Nakamoto. A single Bitcoin represents 100 million satoshis (1 BTC = 100,000,000 sats). Thus, there will only ever be 21 million bitcoin, and there will only ever be 2.1 quadrillion sats. This feature makes Bitcoin more divisible, enabling payments smaller than $0.01 at current prices.

In Bitcoin’s codebase, all values are actually denominated in satoshis, and the unit Bitcoin is only used by markets and those discussing Bitcoin.