Crypto glossary
Satoshi (sat)
A satoshi, or sat, is the smallest unit of bitcoin: one hundred-millionth of a coin, so 1 BTC is equal to 100,000,000 satoshis.
The satoshi is named after Satoshi Nakamoto, the pseudonymous creator of Bitcoin. The protocol itself records every balance in satoshis, and one bitcoin is simply a convenient label for 100 million of them. Wallets can display either unit.
Pricing in sats has become common as the value of a whole bitcoin has risen, because it avoids long strings of decimals. Transaction fees are quoted in satoshis per virtual byte (sat/vB), and the Lightning Network can handle payments of a single satoshi and even track fractions of one internally.
Thinking in sats also helps newcomers see that they do not need to buy a whole coin: any amount down to one satoshi can be held and sent.
Example
A purchase of 0.0005 BTC equals 50,000 sats, and a 140-vbyte transaction paying a fee rate of 5 sat/vB costs 700 sats in fees.
