The satoshi is the smallest unit of the cryptocurrency bitcoin. It is named after Satoshi Nakamoto, the founder(s) of the protocol used in blockchains and the bitcoin cryptocurrency.
There are 2.3 million Bitcoin left to be mined. Surprisingly, even though 18.6 million Bitcoin were mined in just over 10 years, it will take another 120 years to mine the remaining 2.3 million.
Bitcoin can be purchased fractionally, so you don't need to buy a full bitcoin to own some. For example, if bitcoin's price is $10,000, you can purchase 0.1 bitcoin for $1,000.
Bitcoin inventor Satoshi Nakamoto, the anonymous name used by the creators of the Bitcoin cryptocurrency, designed the cryptocurrency essentially as digital gold and capped the Bitcoin maximum supply to mimic the finite quantity of physical gold.