A cryptocurrency (or crypto currency) is a digital asset
Cryptocurrency is designed to work as a medium of exchange using cryptography to secure the transactions and to control the creation of additional units of the currency
Cryptocurrencies are classified as a subset of digital currencies and are also classified as a subset of alternative currencies and virtual currencies.
Bitcoin became the first decentralized cryptocurrency in 2009. Since then, numerous cryptocurrencies have been created. These are frequently called altcoins, as a blend of bitcoin alternative. Bitcoin and its derivatives use decentralized control as opposed to centralized electronic money/centralized banking systems. The decentralized control is related to the use of bitcoins blockchain transaction database in the role of a distributed ledger.
Source: Wikipedia
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