A satoshi is the smallest unit of Bitcoin.
Each bitcoin (BTC) is divisible to the 8th decimal place, so each BTC can be split into 100,000,000 units.
Each unit of bitcoin, or 0.00000001 bitcoin, is called a satoshi.
The satoshi unit is named after Bitcoin’s anonymous creator, Satoshi Nakamoto.
It was first proposed by bitcointalk.org member ribuck. He suggested the name and it has stuck ever since:
シ is the most commonly used symbol for satoshis.
I’m paying you シ100,000 for the coffee, right?
Satoshis are also sometimes referred to as sats.
This is due to a Twitter campaign called #StackingSats that tried to push people to buy small amounts of bitcoin.
There's 100 million sats per bitcoin.— Matt Odell (@matt_odell) May 13, 2019
8 decimal places.
-bitcoin to sats you add commas from the right
-sats to bitcoin you add zeroes to the left
The term “stacking sats” has even made it onto Urban Dictionary:
There are 100,000,000 satoshi in a BTC.
Most fee calculators use satoshis as the unit.
Many wallets, faucets and exchanges also display amounts and fees in satoshis.