Cryptocurrency (or crypto currency) is a digital asset designed to work as a medium of exchange that uses strong cryptography to secure financial transactions, control the creation of additional units, and verify asset transfers.
Cryptocurrencies use decentralized control as opposed to centralized digital currencies and central banking systems.
The decentralized control of each cryptocurrency works through distributed ledger technology, usually blockchain, which serves as a public database of financial transactions.
Bitcoin, first released as open-source software in 2009, is generally considered to be the first decentralized cryptocurrency.
Since the release of bitcoin more than 4,000 altcoins (alternative variants of bitcoin, or other cryptocurrencies) have been created.
