A Cyrptocurrency is a digital asset that can be used as a means of exchange, and is secured using cryptography. The decentralized control of each cryptocurrency works through a blockchain, which is a public transaction ledger, that is distributed across it's users computers. In 2009, Bitcoin was created, and became the first decentralized cryptocurrency, and has to lead to many other cryptocurrencies that been developed since. The other cryptocurrencies besides Bitcoin, are sometime referred to as Altcoins,
As of 2018, there are over 1500 different cryptocurrencies. Some of them are Bitcoin clones that have minor tweaks to the system, and some have taken what Satoshi Nakamoto has created, and made into complex platforms.