One Satoshi is the smallest fraction of a Bitcoin that can currently be sent: 0.00000001 BTC, that is, a hundredth of a millionth BTC.
In the future, when the network grows and Satoshi’s influence decreases, it is possible that this value will change.
Satoshi Nakamoto is the name used by the unknown person or persons who designed bitcoin and created its original reference implementation. As part of the implementation, they also devised the first blockchain database.
In the process they were the first to solve the double-spending problem for digital currency using a peer-to-peer network. They were active in the development of bitcoin up until December 2010.
Nakamoto is believed to have created at least 1 million bitcoins before disappearing in 2010, when he handed the network alert key and control of the code repository over to Gavin Andresen. Andresen later became lead developer at the Bitcoin Foundation.
Nakamoto’s involvement with bitcoin does not appear to extend past 2010. In April 2011, Nakamoto communicated with bitcoin developer Mike Hearn on Bitcointalk, warning Hearn that “the current system is broken” and needed an overhaul.
 Hearn subsequently left the project..
In October 2011, Nakamoto announced that he had “moved on to other things”. Before his disappearance, Nakamoto made all modifications to the source code himself.
He also did not reveal any personal information when communicating with others on the project, and there are no known photographs of him.