Cryptographic Currencies date back to 1988 and DigiCash.
Crypto Currencies have been in use in online games sine the 90’s
Satoshi Nakamoto described the Blockchain in 2009.
The Bitcoin Blockchain began to run in 2010.
Satoshi Nakamoto solved a problem that allowed a distributed and decentralized network to verify all transactions. It can not easily be attacked or controlled since it is run by anonymous ‘participants.’ The participants get paid for running and maintaining the network, through a process known as mining. ‘Miners’ run software that processes all transactions and build blocks. Miners are paid, in Bitcoin, for each ‘block’ they create.
Bitcoin is dividable by 10’s. A Satoshi is one millionth of a Bitcoin. There is a mathematical limit of 21 million Bitcoins. As of 2014 approximately 12 million Bitcoins have been mined.
Satoshi Nakamoto’s paper (technical) https://bitcoin.org/bitcoin.pdf