Cryptocurrency (or crypto currency) is a digital asset based on cryptography, designed to work as a medium of exchange value (just like ordinary money). It uses a distributed ledger system called "Blockchain".
Cryptocurrency is an alternative form of payment to cash, credit cards, and checks. The technology behind it allows you to send it directly to others without going through a third party like a bank.
Cryptocurrency is virtual or digital, meaning that there is no physical coin or bill that owners of the currency possess.
Cryptocurrencies are decentralized meaning that by definition, "blockchains provide a basic level of decentralization because transactions are recorded by all users on the blockchain network". Any changes to the transaction record must be confirmed by the vast majority of blockchain users in order to be recognized as legitimate.