A cryptocurrency is a digital asset whose records are kept on a blockchain and whose owner’s right to dispose of it is proved by cryptographic keys. Examples: Bitcoin, Ether, stablecoins.
In plain words
Cryptocurrencies such as Bitcoin or Ether have no central issuer: transactions are verified by a network of participants under the protocol’s rules. The market sets the value, so the price can swing sharply; where stability is needed for payments, people use stablecoins. Owning a cryptocurrency means holding the private key to an address: losing the key means losing the funds, and a blockchain transfer usually cannot be cancelled. Ukrainian law uses the term “virtual asset” for crypto; there is as yet no full regulation of trading and taxation.
Example. You buy 0.01 BTC on an exchange: the coins are recorded against your address on the Bitcoin blockchain and whoever holds the private key can dispose of them. The hryvnia value of that 0.01 BTC changes every day.