A cryptocurrency (or crypto currency) is a digital asset, which is designed to work as an exchange medium. Cryptography is being used 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 also classified as a subset of alternative currencies and virtual currencies. (Source: Wikipedia)
Bitcoin became the first decentralized cryptocurrency in 2009
Numerous cryptocurrencies have been created ever since. These altcoins, as we like to call them, are an alternative of bitcoin. All altcoins use decentralized control, as opposed to traditional, centralized money, that is controlled by banking systems. Those systems have proven to be less trustworthy than most citizens expected, forcing governments to help banks out using tax money.
More security for end users
The decentralized control is related to the use of bitcoin's blockchain transaction database in the role of a distributed ledger. Basically, the blockchain technology offers more security for the end user if applied carefully.
Most cryptocurrencies are designed to gradually decrease production of currency, placing an ultimate cap on the total amount of currency that will ever be in circulation, mimicking precious metals. Government law enforcement is having a hard time to keep track, mainly because of the security of the crypto currencies. Anonymity is key for the crypto users.
Some people issue concerns about fraud that can be committed using altcoins and bitcoins. That seems a bit odd, because actual 'old' money (bank notes or bank accounts) is used for most known cases of fraud.
As of now, several governments have decided to accept cryptocurrencies as a legal 'monetary' option. In Russia, it is completely legal to buy goods and services with bitcoin, for instance.
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