Bitcoin is the first implementation of a concept called "cryptocurrency", which was first described in 1998 by Wei Dai on the cypherpunks mailing list, suggesting the idea of a new form of money that uses cryptography to control its creation and transactions, rather than a central authority. The first Bitcoin specification and proof of concept was published in 2009 in a cryptography mailing list by Satoshi Nakamoto. Satoshi left the project in late 2010 without revealing much about himself. The community has since grown exponentially with many developers working on Bitcoin.
The reality that Satoshi Nakamoto is real is the biggest mystery up to now. No one really knows if he really created or invented it , or Satoshi Nakamoto is a secret computer experts alliance or he, himself invented it. The world don't even know if he/they are already dead, where they came from or even the IP is he using, but thanks for bitcoin he/they created.